Selective Laser Sintering (SLS)
Selective Laser Sintering (SLS) is an industrial 3D printing process that is ideal for producing end-use parts. In SLS, a laser selectively sinters polymer powder particles, fusing them together to build a part layer by layer. With some of the largest print beds, SLS machines can produce functional plastic parts with isotropic mechanical properties for detailed prototyping or low-volume production of end-use parts. SLS is a cost-effective production method that our customers regularly choose for the most complex parts and those requiring extensive customisation.-
SLS Materials:
PA12
High toughness, heat resistance, low water absorption, corrosion resistance, high fatigue resistance, good surface quality, easy to paint, good dimensional stability, good biocompatibility, small batch rapid parts manufacturing, suitable for functional parts verification.
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How SLS Works:
Preparation:
A 3D model is created using CAD software and sliced into layers.
The sliced file is uploaded to the SLS machine, which controls the laser and powder deposition system.
Powder Deposition:
A thin layer of polymer powder (typically nylon or polyamide) is spread evenly across the build platform using a recoater blade or roller.
Laser Sintering:
A high-powered CO₂ laser selectively sinters (fuses) the powder particles according to the cross-sectional design of the layer.
The laser heats the powder just below its melting point, causing the particles to fuse together without fully melting.
Layer-by-Layer Build:
After one layer is sintered, the build platform lowers by the thickness of one layer (usually 50-150 microns).
A new layer of powder is spread, and the process repeats until the part is complete.
Cooling and Post-Processing:
Once the build is complete, the part is allowed to cool in the powder bed to reduce residual stresses.
Excess powder is removed, and the part may undergo additional post-processing, such as bead blasting, dyeing, or coating, to improve surface finish or aesthetics.
Key Features of SLS:
No Support Structures Required: The unsintered powder acts as a natural support, allowing for the creation of complex geometries without additional supports.
Isotropic Properties: SLS parts have consistent mechanical properties in all directions, making them strong and durable.
High Design Freedom: SLS can produce intricate designs, including internal channels, lattices, and thin walls.
Large Build Volumes: SLS machines often have some of the largest print beds among industrial 3D printers, enabling the production of sizable parts or multiple parts in a single build.
Materials Used in SLS:
Nylon (PA): The most common material, known for its strength, durability, and flexibility. Variants include:
PA 12: Excellent mechanical properties and surface finish.
PA 11: More flexible and impact-resistant.
Glass-Filled Nylon: Enhanced stiffness and thermal stability.
TPU (Thermoplastic Polyurethane): Flexible and elastic, suitable for rubber-like parts.
Composite Materials: Nylon mixed with carbon fiber, aluminum, or other fillers for improved strength and thermal properties.
Applications of SLS:
Prototyping:
Functional prototypes that mimic the properties of final production parts.
End-Use Parts:
Low-volume production of durable, complex components.
Medical:
Custom prosthetics, orthotics, and surgical guides.
Aerospace:
Lightweight, high-strength components for aircraft interiors and drones.
Automotive:
Custom brackets, housings, and ducting.
Consumer Goods:
Customized products, such as footwear, eyewear, and electronics enclosures.
