From powder to finished product – this is how a laser sintering system works: Until a component is finished, a laser sintering system goes through several production steps that are constantly repeated. The starting point is 3D design data, which is cut into many individual horizontal layers in the computer (slicing). In the laser sintering system, these layers are found again. The build platform is first coated with a thin layer of powder. The powder layer is as thin as one layer of the horizontally cut CAD model. The laser in the laser sintering system now writes the geometry of the component in the first layer into the powder, melting it locally. Subsequently, the build platform is lowered by exactly one layer thickness and is again coated with powder. Now, another local melting process takes place according to the geometry of the component in the second layer. In this process, the object geometry just created fuses with the newly applied powder layer. The laser beam is usually guided and controlled by a mirror/scanner on the basis of calculated path data.
In this way, the component or many components are created simultaneously layer by layer in the powder bed.
Learn more about the pros and cons of SLS here.
Advantages of selective laser sintering (SLS)
Fast and precise manufacturing
The 3D fabrications are created in the powder or construction chamber. During production, these are surrounded by the non-melted powder in the interstices, which is why additional support structures are not required. The material used is heated in the powder chamber to just below the melting point, which means that only a small amount of energy is required from the laser to melt the powder. The laser only has to melt the powder for a short moment at a low laser power at the corresponding position, and thus achieves a high degree of precision at maximum construction speed.
After one layer of the powder has been fused by the laser, the build platform lowers by exactly one layer thickness, which can vary between 0.05 mm and 0.15 mm depending on the system and resolution. A squeegee or roller distributes the material evenly on the build platform and the process starts again.