Solid freeform fabrication 

For other uses of the term 'freeform,' see Freeform (disambiguation).

Solid freeform fabrication (SFF) is a collection of techniques for manufacturing solid objects by the sequential delivery of energy and/or material to specified points in space to produce that solid. SFF is sometimes referred to as rapid prototyping, rapid manufacturing, layered manufacturing and additive fabrication.

Techniques

Electron Beam Melting
Fully fused void-free solid metal parts from powder stock
Electron Beam Freeform Fabrication
Fully fused void-free solid metal parts from wire feedstock
Fused deposition modeling
Fused deposition modeling extrudes hot plastic through a nozzle, building up a model.
Laminated object manufacturing
Sheets of paper or plastic film are attached to previous layers by either sprayed glue, heating, or embedded adhesive, and then the desired outline of the layer is cut by laser or knife. Finished product typically looks and acts like wood.
Laser engineered net shaping
A laser is used to melt metal powder and deposit it on the part directly. This has the advantage that the part is fully solid (unlike SLS) and the metal alloy composition can be dynamically changed over the volume of the part.
Selective laser sintering
Selective laser sintering uses a laser to fuse powdered nylon, elastomer, or metal. Additional processing is necessary to produce fully dense metal part.
Shape deposition manufacturing
Part and support material are deposited by a printhead and then machined to near-final shape.
Solid ground curing
Shines a UV light on an electrostatic mask to cure a layer of photopolymers, uses solid wax for support.
Stereolithography
Stereolithography uses a laser to cure liquid photopolymers.
Three-dimensional printing
This label encompasses many technologies, all of which use inkjet-like printheads to deposit material in layers. Commonly, this includes thermal phase change inkjets and photopolymer phase change inkjets.
Robocasting
Robocasting refers to depositing material from a robotically controlled syringe or extrusion head.


Comparison of solid freeform fabrications methods
Method Accuracy (mm/mm)1 Maximum part size (mm)2 Process time (hh:mm)3
Fused deposition modelling 0.005 254 x 254 x 254 (Stratasys)4 12:39
Laminated object modeling 0.01 812 x 558 x 508 (Cubic Technologies) 11:02
Selective laser sintering 0.005 381 x 330 x 457 (3D Systems) 4:55
Solid ground curing 0.006 508 x 355 x 508 (Cubital) 11:21
Stereolithography 0.003 990 x 787 x 508 (Sony) 7:03
Robocasting 0.1 (Fab@Home) 240 x 240 X 240 (Fab@Home) TBD
  1. ^ As of March 2000. Wright, 2001, p. 154.
  2. ^ Grenda, 2006, retrieved June 13, 2006.
  3. ^ As of June 1992. Wright, 2001, p.153.
  4. ^ Wright, 2001, p.153

See also

References