Warp Speed

11/21/2006

From Minnesota Technology TechTrends Newsletter
November 2006

Rapid manufacturing offers efficiencies and product-development techniques that were unheard of a decade ago. Will it prove itself as a truly disruptive technology?

The Star Trek fans readers are no doubt familiar with the Replicator. The device is a practical wonder for the ship’s crew, allowing them to instantly create inanimate objects—clothing, machine parts, steaming cups of tea—via voice commands. (It’s also a handy plot device for the show’s writers, allowing them to solve the pressing problem of how the ship manages to feed its hundreds of crew members during their years-long voyages through space.)

What does any of this have to do with today’s manufacturing realm? As it turns out, more than you might think, thanks to a technology known as rapid manufacturing (RM). The RM industry has been gaining steam in recent years, and is already offering efficiencies and product-development techniques that were unheard of as little as a decade ago.

In a nutshell, RM works like this: A product designer sends a CAD file to a machine that translates the information and creates a three-dimensional product by systematically building up multiple layers of a base material such as plastic or ceramic. Because there’s no need for special setup and assembly, and no need for tooling or special molds, processes that typically take weeks or months to complete can be done in a matter of days—and often at far less cost than a more traditional manufacturing setup that would involve injection molding, dies, specialized jigs, and the like.

It’s no surprise, then, that RM is already being used in such industries as aerospace, automotive, medical, and electronics, primarily for short-run, low-volume projects (typically less than 500 pieces per run). Current applications include everything from gasoline storage cells to medical devices such as spinal implants to ceramic filters for coal-fired power plants, to name only a few. The Boeing Corp. even has created its own RM subsidiary to create complex cooling ducts for some of its airplanes.

While it isn’t quite science fiction, RM does have some remarkable abilities. And this is only the beginning.

Trial runs

RM is the natural evolution of a practice known as rapid prototyping (RP). While both use the same 2D-to-3D production process, the key difference is that RP creates, as its name implies, a product prototype instead of a finished product. Since its introduction in the late 1980s, RP has grown into a $1 billion worldwide industry. And depending on what estimates you believe, it’s still growing too—at anywhere from a 10 to 40 percent annual clip.

As the industry has gotten more sophisticated, and as the technology behind RP systems has developed, a number of industry players have been making the leap to RM. Case in point: Eden Prairie-based Stratasys (http://www.stratasys.com), an RP equipment provider that opened its own RM service bureau, RedEye RPM (http://www.redeyerpm.com), in 2005. According to the company, the division now boasts 60 machines and has produced more than 60,000 prototypes and working products for customers since its inception. The division uses Stratasys’ patented Fused Deposition Modeling (FDM) and PolyJet systems, both of which work by extruding a thermoplastic material, laying it down in multiple layers, and fusing each layer together to form a 3D object. Clients can upload their CAD designs directly to RedEye RPM’s Web site and then wait for the parts to be delivered (typically within three to five business days, according to the company).

While the FDM and PolyJet systems are undeniably cool, they are by no means the only RM technologies in use these days. Here’s a look at some other major types:

Stereolithography is an older process that uses software to convert a CAD model into a series of thin, 5- to 10-millimeter layers. From there, the information is sent to a machine with a laser installed above a vat of photo-sensitive resin. The laser cures the resin, layer by layer, to create the 3D part.

Selective Laser Sintering uses a laser to fuse together tiny particles of plastic, metal, or ceramic powders to create a 3D object. As in stereolithography and FDM, the laser downloads information from a CAD file and builds the object in multiple layers.

Shape Deposition Manufacturing is another layering process, but one which combines elements of both deposition and CNC machining. In essence, each layer is machined after it is deposited, which creates a smooth surface and allows for the creation of layers with undercut, overhanging, and separated elements.

Robocasting is a process developed by an engineer at the U.S. Department of Energy’s Sandia National Laboratories. It uses robotics to manage the computer-controlled deposition of a ceramic slurry—a mixture of ceramic powder, water, and trace amounts of chemical modifiers. The slurry is deposited by a syringe in thin sequential layers onto a heated base. The layers then melt and harden to form a final product.

Next steps

What’s next for RM? Plenty. In the last few months alone, news reports have covered dozens of innovative new applications. An Italian firm has used the process to create a carbon-filled polyamide material that’s ideal for wind tunnel-testing applications. A medical team at Queen Mary University in London used selective laser sintering to create a porous, bioactive polymer composite that acts as a “scaffold” for bone growth in bone-implant applications. The U.S. military recently ordered thermoplastic battery-pack components from Stratasys’ RedEye RPM; the packs allow soldiers to mount flashlights to M16 rifles. According to RedEye RPM, several traditional molding companies had to turn down the order because they couldn’t meet the tight deadline. The military also reportedly has been looking into developing the capability of quickly producing replacement parts for vehicles while on the battlefield.

Mass customization of consumer products offers another area of promise. The prospect of creating individually tailored hockey sticks, hearing aids, dental implements, and jewelry has plenty of manufacturers intrigued. And one firm, Concord, Mass.-based SolidWorks Corp., already is in the process of launching a new consumer-facing division called Cosmic Modelz. Users can log onto to http://www.cosmicmodelz.com and design their own toy action figure online. The finished designs will be sent to Z Corp. (http://www.zcorporation.com), a Burlington, Mass., RM firm, for production and then shipped to the user. Cost per model will range from $25 to $50.

All of this good news aside, the RM industry still faces some significant challenges. It’s only practical for short-run projects. RM machines are currently limited in the size of products they can produce (3 feet long is the maximum). And, at present, RM providers can only produce products out of thermoplastics, waxes, resins, ceramics, and some metals. That’s not enough to satisfy, for example, the boat manufacturer that needs a stainless steel turbine for an outboard engine or the medical device firm looking for a custom-designed titanium ball socket for a hip-replacement operation.

That said, several recent news reports note that both the variety and number of materials has been increasing as the industry matures and as more providers—and more customers—enter the RM field. Will RM machines ever be able to produce large (i.e., bigger than 3-foot-long) products? Probably. Will they be able to create parts out of stainless steel and/or titanium? Maybe, although that may not happen for some time. Will RM ever fully replace traditional manufacturing methods? Probably not. But given how quickly the industry has already grown, it’s safe to assume that anything is possible.