List of 3d printing technologies
Material Extrusion / FDM (Fused Deposition Modeling) / FFF (Fused Filament Fabrication)
Material extrusion devices are the most commonly available — and the cheapest — types of 3D printing technology in the world.
The way it works is that a material (usually plastic filament) is loaded into the 3D printer and pushed through a heated printer nozzle. The melted liquid material is thus deposited onto the build platform, where it solidifies by cooling. The print head continues like this tracing out the pattern of the first layer onto the build plate. After the first layer is complete, the print head moves up one layer height, and starts building the next layer on top of the first one. This continues until the whole object is constructed.
There is a large variety of materials available for FDM type machines, and a large variety in the printers themselves, using the technique described above, or slight variations thereof. (For more information see Material extrusion technologies.)
The wide availability of low-cost FDM printers and the accompanying materials makes the technology a great point of entry to 3D printing, but the quality of the parts is generally less desirable than that of other processes, and low-cost machines might also mean more problems that can arise with the prints.
Vat Polymerization / SLA (Stereolithography) / DLP (Digital Light Processing)
Vat Polymerization is the oldest type of 3D printing. It uses a UV light to solidify (cure) liquid photopolymer resin in a vat in a specific pattern one layer at a time. After every layer the build platform raises by one layer height, and curing the next layer begins, adhering to the bottom of the previous one.
Vat polymerization results in a good surface finish, but it requires [Vat polymerization post-processing|post-processing] and the handling of irritant chemicals.
Material jetting creates objects in a similar method to a two dimensional ink jet printer. Material is jetted onto a build platform where it solidifies and the model is built layer by layer. Material is deposited from a nozzle which moves horizontally across the build platform. Machines vary in complexity and in their methods of controlling the deposition of material. The material layers are then cured or hardened using ultraviolet (UV) light.
The binder jetting process uses two materials; a powder material and a liquid binder. The binder acts as an adhesive between powder layers. A print head moves horizontally along the x and y axes of the machine and deposits alternating layers of the build material and the binding material. After each layer, the object being printed is lowered on its build platform.
Due to the method of binding, the material characteristics are not always suitable for structural parts and despite the relative speed of printing, additional post processing (see below) can add significant time to the overall process.
As with other powder based manufacturing methods, the object being printed is self-supported within the powder bed and is removed from the unbound powder once completed. The technology is often referred to as 3DP technology and is copyrighted under this name.