Direct digital manufacturing
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Direct digital manufacturing is a manufacturing process which manifests physical parts directly from 3D CAD files or data using additive fabrication techniques, also called 3D printing or Rapid Prototyping. The 3D printed part or parts are intended to be used as the final product itself with minimal post-processing.
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[edit] Additive Manufacturing
Additive Manufacturing is also referred to as Additive Freeform Fabrication, Rapid Prototyping, Layered manufacturing or 3D printing. The technique physically constructs or manifests 3D geometries directly from 3D CAD. The history of the process spans approximately 25 years. It was originally known as Rapid Prototyping because the technology was used to make prototypes of parts without having to invest the time or resources to develop tooling or other traditional methods. Since the process was slow, it was used solely for prototyping.
Additive Manufacturing or Direct Digital Manufacturing is an extension of Rapid Prototyping to produce greater quantities of parts. As of 2007, the required machines have become practical in price, speed, reliability, and cost of use. This has led to the expansion of their use in industry. There has been explosive growth in the sales and distribution of the hardware. A new industry has emerged to create software to enable more effective use of the technology. Also, the number of materials that the machines can process has increased greatly in the decade to 2007. [1] Modern machines can utilize a broad array of plastics & metals.
As the speed, reliability, and accuracy of the hardware improves, additive manufacturing may replace or complement traditional manufacturing in creating end-use products. Additive manufacturing eliminates much of the labor associated with traditional manufacturing.
The use of the technology is likely to grow. In 2007 a sub-$4,000 machine was presented. 3D printing bureaus have sprung up around the globe.
[edit] Advantages
1.) Energy efficiency: Only the energy necessary to form the part is expended, and waste is eliminated. This contrasts with conventional machining, in which energy is used to smelt metal into ingots, which become billet materials. These billet materials are then machined, removing a great deal of the material to produce the final part. The energy used to create the original block of material is wasted.
2.) Low material waste: Since the process only forms the desired part, there is almost no waste formed, again in contrast to conventional machining. The absence of waste enhances energy efficiency, as energy is not used to transport or dispose of waste.
[edit] Technologies
There are presently about 25 3D printing technologies. The oldest is layered object manufacturing. The next oldest is stereolithography. More recent technologies include selective laser sintering, inkjet technologies, fused deposition modeling and many variations. All of these technologies take a 3D model, compute cross-sections of that model, and then deposit the cross-sections sequentially on top of each other until the final geometry is achieved.
To visualize how 3D printing works, consider slicing a ham on a meat slicing machine. The slices are cross-sections which can be stacked to reproduce the form of the original ham.
Varying the layer thickness affects the model surface finish. Many methods have been devised to improve surface finishes; these usually slow down the printing process.
[edit] Direct Digital Manufacturing Usage
There are presently around 50 commercially viewable examples of 3D printing being used for tooling or intermediate parts. The technology is still new and its use is directly dependent on users' knowledge of engineering to design a part and effectively use the printing equipment. The growth of the market is nevertheless fast, at 33% annually or better according to Terry Wohlers.
[edit] References
[edit] External links
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The external links in this article may not follow Wikipedia's content policies or guidelines. Please improve this article by removing excessive or inappropriate external links. |
- The Rapid Prototyping Home Page.
- Digital Reality, Inc. - A startup company in Austin, Texas, holds several patents pertaining to mass customization through Direct Digital Manufacturing.
- Ponoko - A New Zealand company that holds several patents pertaining to mass customization using numerically controlled laser-cutting.
