Solid Freeform Fabrication

Solid Freeform Fabrication (SFF) is an approach to fabricating mechanical components that is additive vs. subtractive, such as machining. SFF is also known as Rapid Prototyping (RP).
In SFF, multiple layers of material, each representing a cross section of a desired three-dimensional structure, are deposited one at a time to form a laminated stack.

By using hundreds or even thousands of such layers, extremely complex, freeform, three-dimensional shapes can be produced. SFF technologies in commercial use include StereoLithography (SL), Three-Dimensional Printing (3D P), Fused Deposition Modeling (FDM) and Laminated Object Manufacturing (LOM), to name a few.

SFF technologies are characterized by a number of significant features. First, they are extremely versatile, producing extremely complex shapes (including shapes having internal features that would be impossible to produce by subtractive methods).

Second, they typically involve a fixed process with just a few simple process steps repeated again and again to form each layer, and so can easily be implemented in a single process tool and be automated.

Third, they are driven in a top-down fashion by a three-dimensional CAD model of the desired structure. Due to the CAD technology, subsequent modifications can be promptly implemented.

SFF has been applied to the fabrication of models and prototypes of macroscale mechanical parts, like automotive parts, jet engine parts, and to making tooling for volume production of these parts. SFF has also been successfully applied in biomedical for manufacture of prostheses and other complex parts.

However, there is a growing interest in applying the SFF paradigm to other industries also with each passing day.