A Brief Tutorial
Three dimensional printing (3DP) was developed at MIT. It's often used as a specialized manufacturing process as well as for concept modeling. Among the items manufactured using the process are false teeth, filters of various types and casting patterns.
The process starts by depositing a layer of powder object material at the top of a fabrication chamber. To accomplish this, a measured quantity of powder is first dispensed from a similar supply chamber by moving a piston upward incrementally. The roller then distributes and compresses the powder at the top of the fabrication chamber. The multi-channel jetting head subsequently deposits a liquid adhesive in a two dimensional pattern onto the layer of the powder which becomes bonded in the areas where the adhesive is deposited, to form a layer of the object.
Once a layer is completed, the fabrication piston moves down by the thickness of a layer, and the process is repeated until the entire object is formed within the powder bed. After completion, the object is elevated and the extra powder brushed away leaving a "green" object. No external supports are required during fabrication since the powder bed supports overhangs.
Three dimensional printing offers the advantages of speedy fabrication and low materials cost. Overall, it's the fastest of all additive methods. It is also the only technology for which full color output is available. This makes it an excellent choice for industrial design, scientific visualization and architectural modeling applications. However, the technology does suffer from limitations on resolution, surface finish and part fragility. The number of available materials is very limited and parts must usually be infiltrated with an adhesive before they can be safely handled. While the method is generally quiet and office-friendly, powder handling and infiltration can make this a less than spotless process.
The closest competitor to this process in terms of costs and applications are probably the thermoplastic extrusion methods such as Fused Deposition Modeling® (FDM®). Both processes offer distinct advantages and disadvantages, however, so the choice is fairly easy to make depending on the specific application.
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& Photopolymer-based Systems.
Fused Deposition Modeling (FDM).
& Thermoplastic Extrusion Systems.
Three Dimensional Printing (3DP).
(Selective) Laser Sintering (SLS/LS).
Laminated Object Manufacturing (LOM).
Laser Powder Forming (LPF).