Powder sintering (SLS)

Everything You Need to Know About SLS 3D Printing: The Complete Guide for Industry

3D printing Selective Laser Sintering, or Selective Laser Sintering, is one of the most high-performing additive manufacturing technologies for producing complex functional parts and prototypes. Whether you are an engineer, designer, or entrepreneur, discover how this technology is transforming modern manufacturing.

What is SLS technology?

fused deposition modelling powder bed. Unlike fused filament fabrication (FFF), it uses a high-power laser to fuse fine polymer powder particles (typically nylon) to build a solid structure, layer by layer.

Laser sintering works by using a high-powered laser to fuse small particles of plastic, metal, or ceramic powder together. The powder is spread in a thin layer onto a build platform. The laser then scans across the powder, selectively melting and fusing the particles according to a digital 3D model. Once a layer is complete, the build platform lowers slightly, and a new layer of powder is spread on top. The process is repeated until the entire object is built, layer by layer.

1. Preparation: A trough is filled with preheated polymer powder just below its melting temperature.

2. Fusion A CO2 laser scans the powder bed surface, selectively sintering particles to form a layer.

3. Repetition: The platform descends again, a new layer of powder is spread, and the cycle begins anew.

4. Cooling: Once the printing is finished, the powder block must cool down slowly to avoid warping.

Why choose SLS? Advantages and Disadvantages

The choice of SLS technology depends on your requirements for geometry, strength and cost. Here is a summary to help you decide:

The flagship materials of laser sintering

The success of SLS relies on the versatility of its materials, primarily from the polyamide family:

• PA 12 (Nylon) The industry standard. Perfect balance of robustness and precision.

• PA 11: Bio-based and more flexible, ideal for parts subjected to impact.

• Loaded materials Powders enriched with fibreglass, carbon or aluminium to increase rigidity or thermal conductivity.

Common applications

Thanks to its complete design freedom, SLS is used in many sectors:

• Automotive & Aerospace Air ducts, tanks, light supports.

• Medical: Custom orthotics, surgical guides.

• Consumption: Spectacles, protective covers, prosthetics.

• Tools Heavy-duty jigs and fixtures for production lines.

Our tips for optimising your SLS designs

To make the most of this technology, keep these points in mind:

1. Obviously parts: To save material, hollow out your volumes, but don’t forget to add some drain holes to extract the unfired powder.

2. Functional game Plan for at least 0.5 mm for mechanisms assembled in a single print.

3. Wall thickness A minimum of 1 mm is recommended to guarantee structural integrity.

Do you need a quote for your SLS projects?

Contact our experts or upload your 3D file for an immediate feasibility analysis.

FAQ: Frequently Asked Questions About SLS 3D Printing

Are SLS parts watertight?

PA 12 parts are naturally resistant to moisture, but their porosity may require post-treatment (impregnation or painting) for perfect sealing against liquids under pressure.

Can SLS parts be coloured?

Yes, the pieces typically come out white or grey, but they lend themselves perfectly to dip dyeing, allowing for deep colour penetration.