Rapid prototyping technologies enhance the opportunity for innovation

For those involved in product development, engineering and other form building applications, rapid prototyping (RP) technology can offer excellent delivery for various applications. Prototyping can be used for concept generation, ergonomic testing, test fit, functional testing, and even small batch production.

There are several rapid prototyping technologies available for use, including fused deposition modeling (FDM), stereolithography (STL), selective laser sintering (SLS), and 3D printing. Each of these technologies has advantages and disadvantages.

Fused deposition modeling technology is marketed by Stratasys, which also owns a trademark on the term. Like most other RP processes, FDM works on an “additive” principle by depositing material in layers. A filament of plastic or metal wire is unwound from a spool and supplies material to an extrusion nozzle that can turn the flow on and off. The nozzle is heated to melt the material and can be moved in both horizontal and vertical directions by a numerical control mechanism, controlled directly by a computer-aided design software package. Similar to stereolithography, the pattern is built up from layers as the material hardens immediately after die extrusion.

Stereolithography is an additive manufacturing process that uses a vat of liquid UV-curable photopolymer “resin” and a UV laser to build parts one layer at a time. In each layer, the laser beam traces a partial cross-sectional pattern on the surface of the liquid resin. Exposure to UV laser light cures or solidifies the pattern traced in the resin and adheres it to the bottom layer.

Selective laser sintering is a rapid additive manufacturing technique that uses a high-powered laser to fuse small particles of plastic, metal, ceramic or glass powder into a mass that represents a desired 3D object. The laser selectively fuses powdered material by scanning cross sections generated from a 3D digital description of the part on the surface of a powder bed. After each cross section is scanned, the powder bed is reduced by one layer thickness, a new layer of material is applied on top, and the process is repeated until the part is complete.

3D printing is a unique form of prototyping that is based on traditional rapid printing technology. A three-dimensional object is created by overlapping and connecting successive cross sections of material. 3D printers are generally faster, more affordable, and easier to use than other additive manufacturing technologies. While prototyping dominates current uses, 3D printing offers tremendous potential for retail consumer uses, especially since the cost of production is lower than other methods and the part build time is minimal. In the latest incarnations, 3D color printing is also available. This means that a part can be printed to represent the colors of the finished product, to show label concepts or requirements, or to indicate the results of stress analysis or other Failure Mode Effects (FME) analyses.

For the most part, all rapid prototyping systems require a 3D computer model to start the process. In most cases, a significant amount of file preparation must be done to get a file to generate a correct rapid prototype model.

As part of the innovation process, some companies may employ one or more internal rapid prototyping technologies. However, being a new “edge” technology, many companies can make use of service bureaus to provide their rapid prototyping as the need becomes apparent. Most service bureaus have detailed websites for marketing and serving their customers.

A handful of service bureaus are fairly large companies with numerous employees and locations. Many provide related services and technologies, such as tooling, industrial design, molding, and production. However, service bureaus are often small businesses, and while they may be small, many are vertically integrated and can provide services from concept models to finished functional parts.

Service bureaus tend to specialize in one or more areas, such as injection molding, foundry, etc. Browse a company’s portfolio or cases on its web pages, or discuss previous projects with the company to try to better understand particular areas of expertise. Sculptors have also used the technology to produce complex shapes for fine art displays.

In the near future, rapid prototyping technology will become widespread and even reach the home. However, for now, for timely and expert delivery, using a service bureau is the way forward for most innovative businesses, individuals, and organizations.