Optoelectronics demands the very best

The moldmaker often is the most critical member of a concurrent engineering team. This can be the case even if the project involves production of some kind of simple widget. Imagine if the project involves production of fiberoptic lens arrays out of Amoco's Radel PES; lens arrays with 22 optical vanes that are .0098 inch +/-.0002 thick; spaced .0098 inch apart from one another along a body; each lens with two optical faces at 90¡ connected by a true elliptical periphery whose position has to be held to within +/-.000098 inch. A moldmaker's role in a team concurrently engineering a precision part isn't just critical - it's super critical.

The tooling issues for the production of parallel array fiberoptic lenses were covered in a paper presented at the Molding '97 conference and expo (March 24-26 in New Orleans) by Timothy R. Erwin, technical advisor, engineering, of Pitney Bowes Plastic Components Operations. IMM took you on a guided tour of Pitney Bowes' Plastic Components Operations in Danbury, CT a few years back (See February 1995 IMM, p. 78), and discussed how P-B has used the team concept, both internally and externally, to help it add custom molding work to its captive molding operations. At Molding '97, Pitney Bowes' Erwin let everyone know that a dedicated team of experts can challenge long-standing ideas of just what plastics injection molding can and cannot do. In this case, the team included Pitney Bowes and a moldmaker - Apex Machine Tool Co.

As you might imagine, Apex is a special kind of moldmaker. Privately owned, it makes high-precision ±.0001-inch-tolerance fixtures, gauges, dies, and molds. It was started in 1944 by James Biondi Sr. One of his sons is CEO today, another is president. Apex occupies a 44,000-sq-ft plant in Farmington, CT, 5500 sq ft of which is dedicated to design. ISO certification is expected by summer's end, and two seats of Moldflow will be installed by the end of the year. It employs about 27 designers, three programmers, and 85 machinists.

Precision molds and multiple mold programs for molding machines less than 300 tons are its specialty. The company manufactures approximately 30+ molds annually, accounting for about a third of its $17 million in annual sales. The molds manufactured at Apex are super-high- precision, guaranteeing high volume for the most demanding parts imaginable. It has a long-established tradition of refusing to be the second best in anything it does. "Our best sales force is our customers and our competitors," says Apex's John R. Bruno, vice president of plastics.

Just listen: "I wanted that mold to run the first time. The mold was delivered on time, and the first shots were assembled into functional test units." That's Pitney Bowes' Erwin talking about the lens array mold. These lens arrays are used in a fiberoptic connector developed by IBM's Watson Research Center, 3M's fiberoptics laboratories, and Lexmark's Plastics Technology Center. (Pitney Bowes ran into the job quote on the Internet after Lexmark put it out for bid on the World Wide Web.) Technical product development of parts with such demanding specs is becoming routine at Pitney Bowes. The company saw the job as being ideal for its 50-ton Technoplas Super Injection Molding (SIM) machine.

Unfortunately, lead times for the special kind of tooling this special machine would have been 14 months if the mold had been sourced through Technoplas headquarters in Japan. IBM allowed only 10 months, maximum, to develop the lens array. "You always have the time to do it right the second time, but never enough to do it right the first time," Erwin jokes.

Fortunately, Technoplas had previously worked together with Pitney Bowes and Apex to develop Apex as a U.S. source of SIM tooling components. Technoplas SIM machines operate through closed loop cavity-pressure feedback control, using vacuum-tight molds of exacting dimensions. Mold plates must be flat to within .0001 inch, and the mold bases have to open and close with .0002-inch slide fits to be vacuum-tight. Erwin says such molds require "gaugemaker workmanship."

"When Bruno saw the drawing . . . to say he was excited would be an understatement," Erwin recalls. "Apex leapt at the chance to work on this project."

"We have a great engineering group that can look at things objectively," adds Bruno. "Ho-hum programs aren't our forté. But when we see something like this, associated with companies like Lexmark and IBM, we want to be involved; this was leading-edge technology."

"I was surprised at how easy it was to mold that part. It was getting it out of the mold that was the tough part," Bruno explains. The part filled with no difficulty on the first trial. However, it stuck in the mold due to the lack of sufficient ejection. The product, as designed, allowed for minimal ejection area creating a less-than-desirable condition.

After a brainstorming session among Pitney Bowes, IBM, and Apex, and a part concession allowing for more ejection surfaces, Apex engineers went to work. They redesigned the optical blade inserts and the ejector area. It was decided that precision gauge blocks could be used as the base material. But they'd have to be capable of holding sizes in three dimensions to within ±.00005 inch. After drilling, rough machining, CNC jig grinding and lapping, the best polisher in the shop, working hours on each insert, polished the elliptical surface, removing the final .0001 inch (±.000098 inch). The result? Yield was increased from a few usable parts up to 1000 high-quality lenses, just in time.

"This was a true developmental program, real concurrent engineering, with all of the parties involved understanding it to be a collective enterprise," Pitney Bowes' Erwin summarizes. "Everyone was focused on success." Such teams will continue to push the edge of the technological envelope, and in so doing, propel injection molding into challenging 21st century markets, like the emerging field of optoelectronics. And moldmakers like Apex will play a critical role in teams creating such new niche markets, those that demand the very best from all the super-critical team members.