Fused Deposition Modeling (FDM)
As soon as a layer is finished, the print bed lowers a layer thickness and the next layer is printed. This process is repeated until the complete model has been built.
FDM is one of the most applied technologies.
Operation: Plastic wire, nozzle
Support structure: Yes
Minimum layer thickness: 0.15 mm
Features: Strong and durable models, cheap, trusted technology.
Digital Light Processing (DLP)
DLP is a technique that uses a light-sensitive resin which is cured with the aid of a beamer.
A (very) thin layer of resin is applied to a foil, after which the beamer cures a complete layer of the model in one go. After this, a layer of resin is again applied to the foil and the process is repeated. In contrast to many other techniques, the model is built up from below at DLP.
DLP works with very thin pillars that serve as support for the overhanging parts of the model. These pillars can be easily removed after printing.
Operation: Light sensitive resin and beamer
Support structure: Yes
Minimal layerthickness: 0,0125 mm ( 12.5 µ )
Features: High resolution, smooth surface finish, high details, high speed printing
Selective Laser Melting (SLM)
SLM and SLS are similar techniques in which a powdered base material (metal powder at SLM and plastic powder at SLS) is melted together by a laser via a movable mirror. This process takes place in a sealed room filled with nitrogen to prevent oxidation.
In the left chamber is the metal powder, a roller or coater conveys a layer of the powder to the right chamber and when the laser has melted together a layer is applied. The storage chamber sinks while the building chamber moves up.
In contrast to SLS, support material is required at SLM and this has to be mechanically removed after building.
Operation: Metalpowder, laser
Support structure Yes
Minimal layerthickness: 0,10 mm
Features: Strong and durable parts, good mechanical properties and density
Atomic Diffusion Additive Manufacturing (ADAM)
ADAM is actually based on the FDM technique, but instead of a thermoplastic plastic, it uses a wire bonded metal powder that is transformed into a metal part.
The total process consists of 3 processes. After printing, the part goes to a cleaning unit where the remains of the binding material is removed and then the part is placed in an oven where the metal powder is melted to solid metal.
Technology: ADAM (FDM)
Operation: Metalwire, nozzle
Support structure: Hardly
Minimal layerthickness : 0,10 mm
Features: Strong and durable parts with good mechanical properties . Postprocessing is hardly needed.