Selective Laser Sintering Process / SLS Models
Injection Moulding | Vacuum Forming | Stereolithography | Ultrasonic Welding
The selective laser sintering process builds SLS models using STL files created from a 3D CAD design.
The basic material consists of powder with particle sizes of around 50 µm which are successively spread in layers on top of each other. A computer controlled CO2 laser beam scans the surface and selectively binds together the relevant particles to make the SLS model
SLS Process
During laser exposure, the powder temperature rises above the glass transition point causing the adjacent particles to flow together - this process is called sintering As the powder is solid, it is self-supporting, so unlike the SLA process, supports aren't necessary for SLS models
When considering using the SLS process please bear in mind the following :-
1. The standard accuracy of SLS models is ± 0.2% / ± 0.2mm, but higher accuracy can be achieved.
2. The minimum wall thickness is 1 mm, but living hinges are possible with SLS models at 0.3 mm.
3. The SLS process creates SLS models which typically have a grainy surface with acceptable roughness. For aesthetic and part evaluation models, the stereolithography process is more suitable.
4. PA SLS models can be used for functional tests - snap fits, living hinges, thermal and mechanical loads. Glass filled PA SLS models are suitable for functional tests with high thermal resistance and impact strength. PS SLS models can be used to make lost wax models for investment casting. After PU impregnation, 80 Shore A TPE SLS models are watertight and can withstand a wide range of liquids. SLS models have mechanical properties comparable to injection moulded PA12 parts. Key: PA=Polyamide PS=Polystyrene TPE=Thermoplastic Elastomer
5. Although dimensions aren't limited, SLS models may be made of several sub-parts.
