The ASTM classifies all 3D printing technologies into seven categories namely material extrusion, vat photopolymerization, powder bed fusion, material jetting, binder jetting, directed energy deposition & sheet lamination. As we continue down the road of “what is 3D printing” here are some of the most popular technologies:
Fused Deposition Modeling (FDM) or Fused filament fabrication (FFF)
This is a material extrusion type of 3D printing technology. MakerBot is one of the leading manufacturers of FDM 3D printers and filaments. FDM 3D printers use thermoplastic polymer material in a filament form that is heated and deposited onto a build platform in a layer by layer form to form the complete object.
Stereolithography (SLA) & Digital light processing (DLP)
Stereolithography (SLA) was the first-ever patented 3D printing technology to be developed and commercialized. It falls under the vat photopolymerization category of 3D printing technology. It uses a photosensitive liquid resin material that is cured by a laser. The laser cures the resin point by point in a continuous process to ultimately form the entire object. Digital light processing (DLP) is a similar technology that uses projected UV light in place of a laser which can result in faster printing.
Selective Laser Sintering (SLS)
Selective Laser Sintering (SLS) is a powder bed fusion 3D printing technology that uses powdered polymer materials to form solid objects. This technology also uses a laser to sinter or melt the powder particles and fuse them to form the entire object.
Other technologies like Direct Metal Laser Sintering (DMLS), Selective Laser Melting (SLM), and Electronic Beam Melting (EBM) operate on a similar principle of powdered materials being fused with lasers (electron beam instead of a laser in case of EBM).