Selective Laser Sintering (SLS)
The models are printed layer by layer with a laser that draws thin lines in the powder, which melts and bonds it together to form a thin layer of the model. After a layer is printed, a new layer of fresh powder is spread over the surface by a roller. The printer has a print chamber which is heated to just below the melting point of the powder. The laser beam adds the extra energy to melt the powder, and forms a solid model. After a print job is finished, the result is a big block of heated powder with the printed models contained inside.