Rapid manufacturing is characterized by the following features:

  • Geometry is based on 3D CAD data

  • Is based on adding layers, so that the object is made layer by layer

  • Process is automated and the object is end product

 

Selective laser sintering process is explained with the following sketch. The powder is dispersed in a thin layer on top of a platform inside of the build chamber. The printer preheats the powder to a temperature somewhat below the melting point of the raw material, which makes it easier for the laser to raise the temperature of specific regions of the powder bed as it traces the model to solidify a part. The laser scans a cross-section of the 3D model, heating the powder to just below or right at the melting point of the material. This fuses the particles together mechanically to create one solid part. The unfused powder supports the part during printing and eliminates the need for dedicated support structures. The platform then lowers by one layer into the build chamber, typically between 50 to 200 microns, and the process repeats for each layer until parts are complete.

 

advantages of the technology

  • There are no limitations for the object geometry

  • Thin wall thickness can be done - min. layer thickness 0,5mm

  • No tooling needed

  • Process is automated

  • Process is rather fast

  • Assembly’s can be manufactured in a single print

AND limitations

  • There are limitations for the accuracy; up to +/- 0,1mm

  • Surface roughness is limited; post process for better quality

  • Technology is rather expensive

  • Material selection is limited

Technologycal parameters

PLAStic:                            

  • Max. object dimensions: 650 x 330 x 560 mm

  • Object accuracy: ±0,3 mm

  • Build environment: nitrogen

  • 1 layer thickness: 0,12 mm

  • Min. object wall thickness: 1 mm

  • Laser type: CO2

  • Build chamber temp: 180 °C

  • Materials:

    • Polyamide (PA-12);

    • Polyamide + aluminum (PA-AF);

    • Polyamide + glass fiber (PA-GF)

 

  METAL:

  • Max. object dimensions: 500 x 280 x 345 mm

  • Object accuracy:: ±0,3 mm

  • Build environment: nitrogen

  • 1 layer thickness: 0,03 - 0,1 mm

  • Laser type: fiber

  • Build chamber temp: 200 °C

  • Min. object wall thickness: 0,5 mm

  • Materials:

    • Titanium (TiAl6V4);

    • Aluminum (AlSi10Mg);

    • Stainless steel (316L & C465)