Rapid Prototyping Terms and Definitions

Rapid Prototyping (RP) or rapid manufacturing is the automatic construction of physical objects using solid freeform fabrication.
The first techniques for rapid prototyping became available about 20
years ago and were used to produce models and prototype parts.
Today, they are used for a much wider range of applications and are
even used to manufacture production quality parts in relatively small
numbers. Rapid prototyping takes virtual designs from CAD software,
transforms them into thin, virtual, horizontal cross-sections and then
creates each cross section in physical space, one after the other,
until the model is finished.


Additive Fabrication (AF)
is
the technique of building a part by laying down successive thin layers
of material. With additive fabrication, the machine reads in data from
a CAD model and lays down successive layers of liquid, powder, or sheet
material, and in this way
builds up the model from a series of cross sections.


Desktop manufacturing
or personal fabrication
is the use of a personal computer to drive a printer that deposits (or
catalyses) material in layers to form three-dimensional objects. It can
be used for making prototypes or objects that have limited public
demand.


Direct Digital Manufacturing
is
a manufacturing process that produces physical parts directly from 3D
CAD files or data using additive fabrication techniques, also called 3D printing or rapid prototyping. The 3D printed parts are intended to be used as the final product itself with minimal post-processing.


Electron Beam Melting (EBM)
is
a type of rapid prototyping for metal parts. It is often classified as
a rapid manufacturing method. The technology manufactures parts by
melting metal powder, layer per layer, with an electron beam in a high
vacuum. Unlike some metal-sintering techniques, the parts are fully
solid, void-free and extremely
strong.


Fused Deposition Modeling (FDM)
is
a type of rapid prototyping or rapid manufacturing technology marketed
commercially by Stratasys Inc. Like most other RP processes, FDMworks
on an “additive” principle by laying down material in layers.


Laminated Object Manufacturing (LOMTM)
is
a rapid prototyping system developed by Helisys Inc. In it, layers of
adhesive-coated paper are successively glued together and cut to shape
with a laser cutter.


Low-Volume Injection Molding
creates
functional parts from thermoplastics in short runs of up to 50,000
parts. Offers similar quality and accuracy to parts produced by normal
production tooling, but often faster and at lower cost.


Low-Volume Layered Manufacturing

describes additive fabrication in which the object constructed is the
actual end-use part for manufacturing, rather than a prototype or
model. Sometimes viewed as another term for direct digital manufacturing.


Photopolymer
is a polymer that is cured by exposure to light, often in the ultraviolet spectrum.


Selective Laser Sintering(SLS)
is
a process by which 3D SLS prototypes are formed by fusing or sintering
powdered thermoplastic materials or metals to form functional
prototypes. A claimed advantage to SLS is the range of materials that
can be used, including nylon, elastomers, metals (steel, titanium,
alloy mixtures, and composites) and green sand.


Solid Freeform Fabrication (SFF)
is
a group of related techniques for manufacturing solid objects by the
sequential delivery of energy and/or material to specified points in
space to produce that solid.


Stereolithography (SL)
is
an additive process using a vat of liquid UV-curable photopolymer
“resin” and a UV laser to build parts a layer at a time. On each layer,
the laser beam traces a part cross-section pattern on the surface of
the liquid resin. Exposure to the UV
laser light cures (solidifies) the pattern traced on the resin and
adheres it to the layer below.


STL File
is the
standard data interface between CAD software and a prototyping machine.
An STL file approximates the shape of a part or assembly using
triangular facets. Tiny facets produce a higher quality surface.


Subtractive Fabrication
is
akin to conventional manufacturing techniques like machining, in which
a part is shaped by removing or subtracting material from a piece of
stock. The term
“subtractive fabrication” is intended to differentiate those processes
from those of additive manufacturing so widely used in rapid
prototyping.


3D Printing
is the practice of making a solid (3D) part using an automated additive process.

MPF

Source: :: Make Parts Fast ::