Compressing overall design cycle times often comes down to this question: how quickly can you produce prototype or low-volume production molds? Most OEM designers and custom molders are under a lot of pressure to "make it happen." While you'd like to be able to produce results in six weeks or less, you're painfully aware of limitations to the technology. Or are you?

For this second part of the series on product design, development, and rapid prototyping services, IMM asked Frost Prioleau, president and CEO for Plynetics Express (PE - San Leandro, CA), to update the current technical capabilities and timeframes for prototype and low-volume tooling within RP service bureaus.

"We and other companies in this field offer a bridge between the design community and production injection molders," explains Prioleau. "There are a lot of new rapid prototyping and tooling technologies being developed in an ever-changing environment. One of the services we provide to our customers is helping them make sense out of these types of developments."

Why are OEMs and custom molders turning to companies such as PE for tooling? "Molders and designers are finding that rapid tooling and prototyping technologies appear on almost a quarterly basis," Prioleau says. "It's difficult to stay current unless a company is really focused on rapid prototyping, and it is a capital intensive operation as well. To keep machines state-of-the-art, upgrades must be done annually. But unless you're keeping the equipment busy, it's hard to justify maintaining and upgrading the equipment to keep it state-of-the-art."

As a result, according to Prioleau, outsourcing is becoming more common. "There are two things we do. First, we offer an entire breadth of services and processes rather than relying on one or two. A host of applications may be better suited to one technology or another. We bring the ability to look at each specific application in terms of geometry, production quantities, tolerances, and size, then recommend the process that would be best for those parameters. Secondly, we operate three shifts around the clock, and currently have more RP equipment installed than General Motors. So we can offer shorter lead times on both prototypes and tooling."

In addition to DTM's RapidTool process and 3D Keltool inserts, a new tooling technology is now on the scene, according to Prioleau. At the Rapid Prototyping & Manufacturing '97 conference this April, his company announced the technical launch of PHAST, a rapid tooling process developed by Proctor & Gamble and licensed solely to PE. "PHAST produces metal tooling inserts from reverse geometry patterns in only two days," he says. Total lead time from completion of CAD data to delivery of injection molded parts is typically two to three weeks, including time for mold design, pattern making, PHAST process, mold polishing, cooling lines, ejectors, mold base, and first article parts.

PHAST is an acronym for Prototype Hard And Soft Tooling. The inserts are currently available to customers on a limited basis. The PHAST molds are produced via a proprietary powdered metal process, and are currently molding up to 500 prototype parts in production materials. "We recently molded 600 parts from a single PHAST tool using a Kodak benchmark part adopted by the North American Stereolithography Users Group," Prioleau explains. Parts were shot in fully automatic mode on an 85-ton horizontal press in PC/ABS. "Even after 600 shots," he adds, "the PHAST inserts showed no visible signs of wear. We believe these tools are capable of producing substantially more than 500 parts, but we are still remaining cautious during the beta development period."