[Complete Guide] Selective Laser Sintering – SLS 3D Printing Method

In this guide, we break down the selective laser sintering 3D printing method to help you understand it better even if you’re not too technical.

What Is Selective laser Sintering?

Selective laser sintering (SLS) is a part of the additive manufacturing processes for plastics.

It’s selling point is to make stronger parts for prototyping by using a high-power laser to sinter small particles of polymer powder into shapes.

Polymer Powder To Actual Object

The material is usually nylon in powder form. The SLS powder fusing technology forms powder into a structured part layer by layer until it’s done.

Material Selections

The most common material used for SLS printing is nylon. It’s a very capable thermoplastic material for functional prototyping and end-use production.

Nylon is strong, stiff, sturdy, and durable for parts that need to have these properties. It has near 100 % material density with mechanical properties comparable to parts made with injection molding.

A 3D printed nylon part is impact resistant to wear and tear UV light, heat, moisture, solvents and can be used for many applications

SLS 3D Printer Core Components

A basic SLS printer consists of the following:

  • Heater
  • Build Chamber
  • Powder Delivery System
  • Printed Part
  • Recoater
  • Laser Beam
  • XY Scanning Mirror
  • Laser

The build volume is based on the size of the printer, just like a regular paper printer. The larger object needs a larger printer that fits the print.

Basic SLS 3D Printing Process

3D Model Design

A talented 3D drafter will CAD the model, process it, and make sure it’s in STL or OBJ files that are compatible for the 3D printer to print.


After adjustments and proper printer setting, then the laser scans through the cross-section of the 3D model file and fuses the particles together to form the shape.

Start the print and come back when it’s done. Print time varies based on object size and complexity.

The printer preheats the powder to a specific temperature just below the melting point of the raw material in order for the laser to raise the temperature of a targeted area of the print bed as it traces the build to solidify the part. (A good printer can maintain the temperature inside the printer for maximum consistency)

This process repeats itself until the part is formed completely.

Recommended placing the printer in a safe working safe with good ventilation.

Post Process

Once the part is complete, all parts requires the following steps:

  1. Take the part out of the chamber (be sure to wear protective gear)
  2. Clean off excess powder (Reuseable)
  3. Media blasting the finish part for a smoother surface finish
  4. Primed for paint, coating or electroplating if needed

When To Use SLS Method To Print 3D Parts?

Use SLS 3D printing method for:

  • Fast prototyping & productivity
  • Build functional parts as assembled all together (Because no support is needed)
  • Make impossible parts that are impossible to assemble via traditional methods
  • Nylon substitute for common injection molding plastics
  • Make stronger parts that FDM and SLA can’t
  • Complex design shapes
  • No print support required
  • High productivity at a low cost
  • Reduce product development cycles
  • Less labor required
  • Recoup the initial investment even faster than smaller machines

Already-Proven SLS 3D Printing Applications

  • Build patient specific medical devices
  • Education
  • Rapid prototyping on demand
  • Manufacturing replacement parts
  • Custom parts
  • DIY Hobbies including cosplay

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