1. the development of in-process inspection to assure part quality and suitability for service; and

2. the development of carbon-fiber-reinforced FDM feedstock materials to produce strong, lightweight components.

Stratasys patented and owns the Fused Deposition Modeling (FDM) process. The process creates functional prototypes and manufactured goods directly from any 3D CAD program, using high-performance industrial thermoplastics. The company holds 380 granted or pending additive manufacturing patents globally.

FDM builds three-dimensional parts by melting and advancing a fine ribbon of plastic through a computer-controlled extrusion head, using a three-step process:

1. Pre-processing. This involves “slicing” or sectioning a CAD design into layers. The preprocessing software calculates sections and “slices” the part design into many layers, ranging from 0.005 inches (0.127 mm) to 0.013 inches (0.3302 mm) in height. Using the sectioning data, the software then generates “tool paths” or building instructions which will drive the extrusion head.

2. Production. This is the layering process itself. Two materials, one to make the part, and one to support it, enter the extrusion head. Heat is applied to soften the plastics, which are extruded in a ribbon, roughly the size of a human hair. Alternating between part material and support material, the system deposits layers as thin as 0.005 inch (0.13 mm).

   Core to FDM’s accuracy and precision is the coupling of material feed rates and extrusion head motion. Both are constantly changing to produce a flat ribbon of material that measures from 0.008 inch to 0.038 inch wide (0.20 mm to 0.97 mm) and as fine as 0.005 inch high (0.13 mm). On the highest performance FDM machines, part accuracy or tolerance reaches as high as 0.003 inch (0.08 mm), which rivals injection molding.

3. Post-processing. When the part is complete, the operator either washes or strips away the support material that held the part in place.

FDM machines have build volume capacities ranging roughly from 288 cu. in. to 31K cu. in. (4719 cu. cm to 508K cu. cm).

Stratasys technology has been used in the automotive manufacturing industry for more than twenty years; automotive design and manufacturing engineers use FDM technology for modeling and prototyping, as well as manufacturing of end-use parts.

BMW, for example, uses FDM at its plant in Regensburg, Germany, not only for vehicle design prototyping, but some direct digital manufacturing of hand-tools for automobile assembly and testing.

Weight reduction has a major impact on fuel consumption. For example, on a commercial aircraft, a 500-pound weight reduction results in a quarter-million-dollar savings in fuel costs each year. The overarching goal of the DOE initiative is to reduce the energy usage of US industry, commercialize new products more quickly, and revitalize the global competitiveness of U.S. manufacturing.

Beyond reducing energy use via lighter-weight transportation vehicles, the additive manufacturing (3D printing) process itself is more efficient than traditional subtractive manufacturing processes, such as machining parts or machining production tools and molds.

The additive process can reduce the energy impact of manufacturing. It reduces material consumption, waste streams, large investments into metal tooling, warehouse costs and transportation costs. You don’t have to bring in material just to machine 75% of it away as with traditional manufacturing. Additive manufacturing deposits material only where it’s needed to grow a part.

The initiative with Oak Ridge presents a significant opportunity, particularly in the aerospace and automotive industries, to enable lightweight high performance products to reach the market quicker and at lower costs.

—Stratasys Vice President of Direct Digital Manufacturing Jeff DeGrange

Stratasys Inc. markets its products under the brands Mojo, uPrint and Dimension 3D Printers and Fortus Production 3D Printers. The company also operates RedEye On Demand, a digital-manufacturing service for prototypes and production parts. Stratasys manufactures 3D printers for Hewlett Packard, which it sells under the brand Designjet3D. In 2011 Stratasys acquired 3D printer maker Solidscape Inc.

According to Wohlers Report 2012, Stratasys had a 41.5% market share in 2011, and has been the unit market leader for the tenth consecutive year.

Resources

• ORNL Additive Manufacturing brochure