Rapid Manufacturing for Mass Customization: Good Report in DESIGN NEWS Analyzes Recent Development

Joseph Ogando, Senior Editor of DESIGN NEWS, a trade publication, recently published a great feature article on “ Rapid Manufacturing's Role in the Factory of the Future”.

It reports on the use of laser sintering and similar direct manufacturing technologies not just to make prototypes but also to turn out production parts. It’s a practice that goes by many names — including rapid manufacturing, direct digital manufacturing, solid freeform fabrication and low-volume-layered manufacturing. All of the names refer to the use of additive fabrication technologies, which were initially intended for prototyping, to make finished goods, instead. Rapid manufacturing is considered to be one of the main enablers of mass customization of the future.

The report has a number of nice case studies and analyzes the main challenges or rapid manufacturing:

The biggest barrier in the coming years is seen with regard to materials. Some additive parts simply don’t measure up to their molded, machined and cast counterparts when it comes to tensile and other mechanical properties. … Another material issue involves freedom of choice. With additive technologies, engineers currently have to settle for a limited materials line-up. But as the article shows, the scope of applicable materials is fast growing.

A second barrier is seen in the persistent lack of design data. “it’s not so much that current prototyping materials have some shortcomings as the fact engineers have no way of knowing exactly what those shortcomings are.” The article cites a lack of long-term creep and environmental data for additive plastic parts and fatigue data for metals as the most glaring examples of this data deficiency. But rapid manufacturing observers expect more and more data will become available as direct digital manufacturing becomes more popular. In the meantime, large OEMs with stringent manufacturing requirements have worked to develop their own property data.

A third barrier quoted in the report are the capabilities of the existing machinery. Making good production parts every day ups the ante on process repeatability, quality control, throughput and reliability. “Today’s additive fabrication systems aren’t completely ready for prime time. They’re still primarily prototyping machines that you can coax into working as manufacturing systems”´, an industry expert is quoted in the report.

But despite these limitations, the article comes to a positive conclusion:

“With all these factors weighing against direct digital manufacturing, you might wonder, why bother? But, these additive systems already offer design benefits that can offset their manufacturing limitations.

For one, additive machines can produce complex part geometries without regard to conventional manufacturing limitations. Additive fabrication methods based on powder metal beds, for example, can enable parts with interior cavities and features that could not be machined or cast — at least not in an economical one-piece part. ... The upshot of all this design freedom, and the benefit most cited by advocates of direct digital manufacturing, is parts consolidation.

How long will it take for engineers to recognize the design benefits associated with additive processes? Todd Grimm, a consultant to the rapid prototyping industry, thinks it could take 10 or even 20 more years given the current lack of familiarity with additive machines and the technical barriers associated with the machines themselves. …

For a handful of applications, though, the future is now. The best known and highest volume direct digital manufacturing niche has, so far, involved applications where mass customization plays a role. 3D Systems’ Reichental points to the hearing aids as one example and also says RM machines have seen use in the production of casting tools for Invisalign braces. And as the additive machines in general become more capable, … they’ll play a stronger role in other kinds of customized medical and dental devices whose geometry is tailored to the requirements of individual patients.”

Context:
- Read the full article here: Joseph Ogando, Rapid Manufacturing's Role in the Factory of the Future, Design News´, 26 July 2007

- Other reports on rapid manufacturing in this blog.

- Browse the program of the MCPC 2007 to explore talks and presentations on rapid manufacturing during the conference.