Selective Laser Sintering (SLS) is an industrial 3D printing method that creates precise prototypes and functional production parts in as little as one day. It offers a range of nylon-based materials and thermoplastic polyurethane (TPU) that produce highly durable final parts with properties like heat resistance, chemical resistance, flexibility, and dimensional stability. Since SLS does not require support structures, it allows for easy nesting of multiple parts in a single build, making it a cost-effective solution for producing higher volumes of 3D-printed parts.
Typical applications of SLS include:
Discover how SLS utilizes real thermoplastic and elastomeric materials to create parts with excellent mechanical properties. The final parts are ideal for testing future injection molding designs or for use as functional, end-use components.
Vapor smoothing is now offered for select 3D-printed nylon parts. This process smooths out rough surfaces, leaving parts with a glossy, visually appealing finish.
Our essential guidelines for selective laser sintering highlight key design factors that improve part manufacturability, enhance the visual appearance, and shorten overall production time.
| US | Metric | |
|---|---|---|
| Nylon and TPU Materials | 12.6 in. x 10.6 in. x 16 in. | 304mm x 269mm x 406mm |
| PP (Polypropylene) | 12.6 in. x 10.6 in. x 10.6 in. | 304mm x 269mm x 269mm |
| PA12 | 19 in. x 19 in. x 17 in. | 482mm x 482mm x 431mm |
| US | Metric | |
|---|---|---|
| Nylon and TPU Materials | 12.6 in. x 10.6 in. x 16 in. | 304mm x 269mm x 406mm |
| PP (Polypropylene) | 12.6 in. x 10.6 in. x 10.6 in. | 304mm x 269mm x 269mm |
| PA12 | 19 in. x 19 in. x 17 in. | 482mm x 482mm x 431mm |
| US | Metric | |
| Minimum Wall Thickness | 0.030 in. | 0.762mm |
| US | Metric | |
| Nylons | 0.03 in. | 0.762mm |
| PP and TPU | 0.04 in. | 1.01mm |
For properly designed parts, tolerances of ±0.010 in. (0.25mm) along with 0.1% of the nominal length are typically achievable. However, tolerances may vary depending on the geometry of the part.
Parts with larger dimensions (>7 in.) and thin features are more prone to warping. To ensure stability, we recommend maintaining a consistent thickness of 0.125 in. (3.175mm).
| Standard | Bead blast to remove all powder, which leaves a consistent overall texture. |
| Vapor Smoothing | Significant reduction of surface roughness from 250+ μin RA (as-printed) to 64 – 100 μin RA (after smoothing). Available for PA11 Black. |
| Custom | Secondary options include a primer or dye color that can be applied as well as taps and inserts. |
| Standard | Bead blast to remove all powder, which leaves a consistent overall texture. |
| Vapor Smoothing | Significant reduction of surface roughness from 250+ μin RA (as-printed) to 64 – 100 μin RA (after smoothing). Available for PA11 Black. |
| Custom | Secondary options include a primer or dye color that can be applied as well as taps and inserts. |
| Standard | Bead blast to remove all powder, which leaves a consistent overall texture. |
| Vapor Smoothing | Significant reduction of surface roughness from 250+ μin RA (as-printed) to 64 – 100 μin RA (after smoothing). Available for PA11 Black. |
| Custom | Secondary options include a primer or dye color that can be applied as well as taps and inserts. |
PA 11 Black (PA 850) offers a combination of flexibility and ductility while maintaining strong tensile strength and temperature resistance. These qualities make PA 850 a versatile material for functional and dynamic parts.
Key Benefits
PA12 Black offers excellent mechanical properties and chemical resistance, making it perfect for functional parts and prototypes.
Key Benefits
PA 12 White (PA 650) is a versatile material ideal for general-purpose applications such as functional and end-use parts. It is the strongest among unfilled nylon materials and offers slightly higher stiffness compared to PA 11 Black.
Key Benefits
PA12 40% Glass-Filled (PA614-GS) is a nylon powder enhanced with 40% glass spheres, which provides increased stiffness and excellent dimensional stability. This material is ideal for applications that demand long-term wear resistance. However, due to the glass content, it has lower impact and tensile strength compared to other nylon-based materials.
Key Benefits
Polypropylene Natural provides exceptional chemical resistance, making it one of the top choices among SLS and MJF materials. This material is both tough and durable while maintaining flexibility, and it is resistant to most acids. Additionally, it is a lightweight option.
Key Benefits
TPU 70-A is a white thermoplastic polyurethane known for its rubber-like flexibility and elongation, as well as its strong abrasion and impact resistance. This material is perfect for applications such as seals, gaskets, grips, hoses, or any part requiring superior resistance under dynamic loading conditions.
Key Benefits
| Material | Color | Tensile Strength | Tensile Modulus | Elongation |
|---|---|---|---|---|
| PA 11 Black (PA 850) | Black | 7.54 ksi | 261 ksi | 30% |
| PA 12 Black | Dyed Black | 6.7 ksi | 276 ksi | 13% |
| PA 12 White (PA 650) | White | 7.25 ksi | 290 ksi | 11% |
| PA12 Value | Off White | 6.7 ksi | 276 ksi | 13% |
| PA 12 Mineral-Filled (Duraform HST) | Light Gray | 5.51 ksi | 450 ksi | 3% |
| PA 12 40% Glass-Filled (PA 614-GS) | White | 7.25 ksi | 522 ksi | 5% |
| Polypropylene Natural | Natural | 2.61 ksi | 123 ksi | 15% |
| TPU 70-A | White | 580 psi | — | 210% |
| Material | Color | Tensile Strength | Tensile Modulus | Elongation |
|---|---|---|---|---|
| PA 12 White (PA 650) | White | 50.0 MPa | 2,000 MPa | 11% |
| PA12 Black | Black | 46 MPa | 1,900 MPa | 13% |
| PA 11 Black (PA 850) | Black | 52 MPa | 1,800 MPa | 30% |
| PA12 Value | Off White | 46 MPa | 1,900 MPa | 13% |
| PA 12 Mineral-Filled (Duraform HST) | Light Gray | 38 MPa | 3,100 MPa | 3% |
| PA 12 40% Glass-Filled (PA 614-GS) | White | 50 MPa | 3,600 MPa | 5% |
| Polypropylene Natural | Natural | 18 MPa | 848 MPa | 15% |
| TPU 70-A | White | 4.0 MPa | — | 210% |
These values are estimates and can vary based on several factors, such as machine settings and process conditions. As such, the information provided is not legally binding or guaranteed. For critical performance requirements, it is recommended to conduct independent testing of the additive materials or finished parts.
The surface finish of SLS parts tends to be rougher than that of parts produced by other 3D printing technologies, typically ranging from 100-250 RMS. To enhance the finish, most parts are bead blasted to remove any remaining loose powder and achieve a smooth matte surface. For PA11 Black parts, vapor smoothing is a post-processing option available, which results in a surface roughness between 64 – 100 μin RA.
Material: PA12 40% Glass-Filled (PA614-GS)
Resolution: Normal (0.004 in. layer thickness)
Finish: Standard
Material: PA11 Black (PA850)
Resolution: Normal (0.004 in. layer thickness)
Finish: Standard
We utilize advanced SLS technology, including the sPro140 machines, which offer the largest sintering build volume in the world. These machines are equipped with fully digital, high-speed scanning systems, ensuring exceptional process consistency. Their closed systems for powder blending and delivery guarantee reliable part quality. Additionally, we use sPro60 machines, designed for high throughput and compatible with a variety of materials.
The SLS process begins with the machine sintering each layer of the part’s geometry onto a heated bed filled with nylon-based powder. Once a layer is fused, a roller spreads the next layer of powder across the bed. This process continues, layer by layer, until the part is fully built.
After the build is completed, the entire powder bed containing the parts is transferred to a breakout station, where it is elevated, and the parts are carefully removed. A manual brushing process is first used to eliminate most of the loose powder. The parts are then bead blasted to remove any remaining powder residue before moving on to the finishing stage.
Take a virtual tour of our state-of-the-art additive manufacturing facility in North Carolina, one of the largest 3D printing operations globally. See firsthand how we produce high-quality prototypes as well as fully functional end-use components and assemblies.
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