Skip to content
Aerospace & Defense 3D Printing Services 19 Nov 2025

SLS Printing

Written by

updates@lform.com

How Does SLS Work?

01 Design & Printing Preparation

The part begins as a CAD file that describes its geometry and features in three dimensions. This file is imported into “slicer” software, which converts it into layers that can be understood by an SLS printer. The bed of the printer is filled with powdered resin, usually nylon or polyurethane. The build chamber is then heated until just below the melting point of the resin. This reduces the amount of energy needed for the laser to sinter the material.

Design & Printing Preparation_SLS
02 The Printing Process

A roller spreads a thin layer of powdered resin across the build platform. A laser selectively sinters its particles together, following the instructions from the slicer file. The unfused powder remains in the build chamber, where it acts as a support structure. The process repeats, building the part layer by layer. SLS doesn’t melt particles together. It fuses them at the atomic level. This turns the powdered raw material into a strong, solid structure.

The Evolution and Applications of 3D Printing Technology: Advancements, Challenges, and Future Prospects
03 Post Processing

The completed part is excavated from the powder cake. The part is cleaned of unsintered powder, often using brushes or compressed air. It can be recycled for future part builds. SLS parts may be media blasted or vapor smoothed to improve their surface texture. Other finishing options include dyeing, painting/coating, post machining and placing of inserts. SLS enabless fast, low-cost production of prototype or limited-run production parts.

sls-luggage-tags-website

Is SLS Right For Your Project?

Advantages

  • Proven Technology

    Of all the 3D printing technologies, SLS is one of the most mature and widely used. It has a strong track record of success as a rapid prototyping and production tool. SLS parts have an excellent reputation in many diverse applications.

  • Complex Geometries

    SLS can print complex and intricate parts with fine details. That makes it well-suited for producing functional prototypes and end-use parts with unique shapes.

  • Produce a Large Volume of Parts Quickly

    Multiple parts can be produced at the same time in a single build. The laser used during SLS has a quick scanning speed. That means high throughput at a low cost per part.

  • Low Cost Per Part

    Leftover powder can be reused and support structures are not needed. Also, post-processing is less labor intensive than with other 3D printing methods. That makes SLS parts very affordable.

  • Design Flexibility

    This industrial 3D printing process enables you to build parts with complex geometries, moving parts and pieces with interior components. That’s because it doesn’t require support structures.

  • Superior Mechanical Properties

    Because of the strong bonds between layers, parts produced using SLS tend to have excellent isotropic properties. That means they have similar tensile strength and hardness across all three axes. These characteristics make this commercial 3D printing process an excellent alternative to injection-molded parts.

  • Colorability

    SLS parts have porous surfaces. That means they can be enhanced using a variety of colors and dyes.

Disadvantages

  • Surface Quality

    Parts produced using SLS tend to have a porous surface and may need to be sanded or coated to achieve the required surface finish. One common treatment Fathom uses on SLS parts is vapor smoothing, which produces a smooth, waterproof surface.

  • Time-Consuming Post-Processing

    Depowdering parts after printing can be time-consuming. Parts must be designed with escape holes to enable the removal of powder trapped inside any hollow cavities. SLS parts also require a lengthy cooling process.

  • Shrinkage

    SLS parts tend to shrink slightly as they cool. To maintain dimensional accuracy, engineers need to plan for this when designing SLS parts.

  • Warpage

    Due to the high heat of the printing process, SLS parts can sometimes warp or deform. That can affect their accuracy and dimensional stability. Your Fathom engineering expert can help you tweak your part designs to minimize or avoid this problem.

  • Limited Material Selection

    SLS materials from Fathom are limited to TPU 88A and five types of Nylon.

Applications Showcase the Versatility of SLS

Medical: Custom-fit prosthetics, orthotic, and surgical guides are common uses of SLS because of the precision it makes possible and the biocompatibility of SLS materials.

 

Aerospace: Lightweight components that can withstand high stress and temperatures, such as ducting, brackets and housings.

 

Consumer Goods: Products like custom eyewear, intricate jewelry designs, footwear and sporting equipment benefit from the ability to create complex and durable parts.

 

Automotive: Used for prototyping and creating functional parts, including snap-fit and living hinge components.

 

Manufacturing: Often used for low-volume production runs and creating parts that are difficult or expensive to make with traditional methods like injection molding.

 

Functional Prototypes: SLS is a popular choice for functional prototypes that require strength, heat resistance or complex mechanical joints, allowing designers to test designs thoroughly before mass production.

Case Studies Block

What Can SLS be Paired With?

Selective Laser Sintering isn’t just for rapid prototyping. It can be used to produce small quantities of production parts – ideal if you’re waiting for your injection mold tooling to be built.

 

SLS works with thermoplastics. That means it can be used to quickly create functional prototypes for new product designs. Once your part design is finalized, you can transition to injection molding for production. With our cross-functional engineering expertise, we can help you tweak your part designs so they work well in both prototype and production environments.

SLS can be used to build work-holding fixtures to secure metal parts for CNC machining. It’s perfect for larger jigs and fixtures because of the large build volumes SLS makes possible, small feature accuracy and mechanical strength.

If tight tolerances are needed, a part can be 3D printed with extra material on critical surfaces. They can then be machined to the required tolerances.

Traditional Technologies That Can Benefit from SLS

Selective Laser Sintering can be used to build part designs that aren’t possible using traditional manufacturing methods such as CNC machining and sheet metal fabrication.

 

It also enables fast, low-cost production of prototype or limited-run production parts – without the tooling required to make injection-molded parts.

Why Choose Fathom for SLS 3D Printing?

Share this article: