Selective Laser Sintering
SLS Technology for Support-Free Functional Parts
Powder bed fusion for complex nylon geometry, no support structures, balanced mechanical behavior, and practical low-volume production.
Why engineers use SLS
- No support scars on complex geometry
- Functional PA12 and PA11 nylon parts
- Economical small batch manufacturing
- Internal channels, lattices, and assemblies
How SLS works
From polymer powder to finished nylon parts
SLS builds parts layer by layer inside a self-supporting powder bed, then moves through cooling, cleaning, inspection, and finishing.
- 01
Powder deposition
A thin polymer powder layer is spread evenly across the heated build platform.
- 02
Laser sintering
A CO2 laser selectively fuses powder particles according to each CAD cross-section.
- 03
Layer stacking
The platform lowers, new powder is applied, and the next cross-section is sintered.
- 04
Controlled cooling
The full build cools inside the powder bed to reduce stress and warping.
- 05
Cleaning and finishing
Parts are excavated, blasted, inspected, and finished for use or delivery.
Core advantages
Why SLS is useful for engineering teams
No support structures
Unsintered powder supports the part, enabling internal channels, undercuts, lattices, and nested batches.
Functional nylon parts
PA12, PA11, and PA12GB deliver useful toughness, impact resistance, and engineering performance.
Complex geometry freedom
SLS can consolidate assemblies, reduce fasteners, and print forms that are difficult to machine.
Batch efficiency
Multiple parts can be packed in one build volume, making SLS practical for pilot runs and spare parts.
Consistent mechanical behavior
Powder bed fusion gives more balanced strength than direction-sensitive extrusion processes.
Finish flexibility
Raw, dyed, polished, painted, or smoothed finishes can support both functional and presentation needs.
Design guidance
Design rules that prevent failed SLS parts
Good SLS parts start with wall thickness, clearance, powder removal, and finishing assumptions.
Read design guideWall thickness
Keep functional walls around 1.0-1.5 mm or thicker depending on geometry and load.
Clearance
Use at least 0.3-0.5 mm for moving assemblies and mating printed features.
Escape holes
Add powder escape holes for enclosed cavities and hollow sections.
Threads
Use inserts or post-machined threads when repeated assembly strength matters.
Large flat parts
Add ribs, curvature, or split lines to reduce warping risk.
Fine text
Raised or engraved text should be large enough for powder removal and finishing.
Process comparison
When SLS is the right manufacturing choice
FAQ
Technical questions before quoting
How does SLS differ from FDM and SLA?
SLS prints nylon powder without support structures and produces functional parts with more balanced mechanical behavior. FDM is usually cheaper but has visible layers and direction-sensitive strength. SLA is smooth and detailed but typically more brittle.
What is the surface quality of SLS parts?
Raw SLS parts have a matte, slightly grainy texture. Dyeing, polishing, painting, bead blasting, and vapor smoothing can improve appearance and touch.
What materials are available for SLS printing?
TPM3D supports PA12, PA11, glass-filled PA12GB, and engineering materials for prototypes, functional parts, and small batch production.
When should I choose SLS for production?
Choose SLS when you need functional nylon parts, complex geometry, low-volume production, no tooling cost, or faster iteration than injection molding.