WOBURN, MASS. — Tiny bubbles will invade NPE 2000, but don't go looking for the Lawrence Welk reunion tour. Instead, the bubbles at McCormick Place will come from the MuCell process.
Trexel Inc., which is commercializing the process, plans a coming-out party of sorts at the show. At the last NPE, in 1997, the company's booth showed pictures, but no actual product.
"We had a technology and we were fishing for relevant applications," said David Bernstein, Trexel's president and chief executive officer.
This June it's a different story. Trexel officials, and machinery companies that have licensed MuCell, are predicting widespread use of the bubble process.
Bernstein thinks that, in the next five to 10 years, from one-quarter to one-third of all injection machines worldwide could be running MuCell.
MuCell will be running "live" on injection molding presses from three machinery companies — Engel North America, Milacron Inc. and Arburg Inc. At Trexel's booth (S4144), the company will focus on how the bubbles can enable a molder to enter new markets.
MuCell works by adding microscopic bubbles — eight or nine placed side-by-side equal the thickness of a human hair — to injection molded, extruded or blow molded parts. Through carefully controlling temperature and pressure, carbon dioxide or nitrogen gases are brought to a supercritical state. That means the gas has properties of both a liquid and a gas. Together with the plastic resin, the gas creates a single-phase solution. Bubbles form as the melt goes into the mold.
Trexel supplies the metering equipment system and a Trexel-designed screw and barrel.
Because the process imparts a slight swirling pattern on parts, MuCell's early target markets are parts that do not require perfect finish, such as under-hood car parts, internal printer components or thin-wall parts for cellular phones.
In injection molding, the biggest market, the process results in lighter-weight parts that use less resin, faster cycle times, lower molding pressure and temperature and lower melt viscosity, according to Trexel. Internal pressure from the bubbles reduces warping. Because of the lower temperatures, parts cool faster.
MuCell has come a long way since NPE 1997, and an even longer way from its roots at the Massachusetts Institute of Technology. Nam Suh, head of MIT's Mechanical Engineering Department, invented a method to control the bubbles, first in a batch process and later in extrusion.
Suh decided to start a company to commercialize the process. Seeking venture capital, in 1995 Suh approached Alexander d'Arbeloff, an MIT alumnus who founded Teradyne Inc. in Boston, a major producer of testing equipment for the electronics and telecommunications semiconductor industry. D'Arbeloff agreed to organize a group of investors. He also brought in Bernstein, a former Teradyne executive, to run Trexel.
"The university took this to the point where they had done something unique," Bernstein said. "But the gap between what they had done and any possible commercial value was enormous."
Suh remains a member of Trexel's board of directors.
Bernstein said Trexel wants to go public in one to two years. During a visit in late March, the Woburn headquarters, tucked away in a nondescript industrial park, looked like a classic high-tech start-up company. Trexel's 35-odd employees scramble down narrow hallways to cubicles separated by aging, yellow dividers. Boxes overflow with plastic parts. Piled everywhere are white food containers, a thin-wall molding project. A new executive sets up shop on a folding table next to a tiny lunchroom.
Looks can be deceiving. About one-third of the employees hold advanced college degrees. Others are technical experts.
"We're not hiring from down the street," Bernstein said. "We're really going out and picking people out of companies all over the United States to come here."
On the eve of NPE, things are jumping in Woburn. Six machinery manufacturers have now become MuCell licensees: Engel, Milacron, Arburg, Husky Injection Molding Systems Ltd., Battenfeld GmbH and Japan Steel Works Ltd. The Engel license covers both Engel's U.S. operation and its headquarters company in Austria. After initially licensing MuCell for its Uniloy structural foam molding machines, Milacron last summer added injection presses and blow molders as well.
Machinery companies pay only a small engineering fee to gain a license to offer MuCell as an option, Trexel said. The bulk of license fees will come from processors, which become licensees when they buy an injection press with MuCell or retrofit an existing machine.
"The end-user license fee can be as low as $5,000 and as high as $50,000 per machine, per year," Bernstein said. "It's an annual, machine-based license. That depends on the size of the machine and whether or not people are using commodity resins or engineering resins."
After seven years, the end-user license is paid off.
By the end of June, the company expects to have issued 30-40 processor licenses. Most will go to injection molding operations, and most of those companies don't want to make their plans public yet, citing competitive reasons.
A few molders have gone public as MuCell licensees, including Injectronics Inc. of Clinton, Mass., and Mar-Lee Cos. of Fitchburg, Mass.
Officials at machinery makers that have licensed MuCell echo Trexel's bullish outlook, mainly because customers are asking for it.
Wolfgang Meyer, president of Battenfeld of America Inc. in West Warwick, R.I., said strong customer interest has been a pleasant surprise.
"The potential will be probably in thin-wall parts more so than in thick-wall parts. But an issue in the end remains what do you do with the surface," he said.
Lower viscosity — meaning the plastic flows easier — makes thin-wall molding a key market for Trexel, according to David Pierick, Trexel's vice president of MuCell molding. "The [injection molding] machines have actually reached their limit now, in terms of being able to go thinner. Our process allows them to go thinner," he said.
At NPE, Battenfeld will show MuCell parts, but the company does not plan to do MuCell molding in Chicago, Meyer said.
"I can tell you the request for MuCell has been quadrupling in the past few months," said Kai Jacobsen, Engel North America's manager for process engineering and development. "We can certainly see the potential for this technology to go up, exponentially."
Engel, the first MuCell licensee, built the prototype injection press at its Guelph, Ontario, plant. The first machine was an old-fashioned plunger machine, with a fixed screw. Engel also made the second MuCell press, with a standard reciprocating screw.
Jacobsen said MuCell fits well with Engel's tie-barless machines. MuCell allows bigger parts to be run on relatively small machines, and machines with no tie bars can accept large molds.
At NPE, Engel will run MuCell on a 1,000-ton press molding a dome for industrial lighting. Jacobsen and Pierick also will present a paper on the technology at the Society of Plastics Engineers' Antec this week in Orlando, Fla.
MuCell got another boost in March. DuPont announced glowing results from MuCell trials using glass-reinforced Crastin polybutylene terephthalate and Zytel nylon. DuPont was able to reduce injection clamp pressure by up to 50 percent, compared with traditional solid parts.
MuCell's low pressure "can be crucial in avoiding damage to delicate electronic assemblies" when molding plastic around electronic components, DuPont said.
