For one equipment supplier, gas-assist injection molding bears close resemblance to the Hunchback of Notre Dame.
``[Like the hunchback], it's been housed in a closet for years,'' said Paul Dier, technical specialist with the Plastics Technology Group of Bauer Compressors Inc. in Clinton Township, Mich. ``The shame is, so many molders could have benefited from the technology but have been afraid to use it.''
Like many in the industry, Dier wears his frustrations openly. First arriving commercially in the early 1980s, gas-assist molding was considered a rising star capable of lowering processing costs and easing the production of complex parts.
Today, those benefits remain intact. The low-pressure process has been used for large or thick parts, and in trickier sections with ribs or bosses. The equipment pushes compressed nitrogen gas into a mold behind the resin, forcing the material to flow uniformly.
Yet the growth of this promising process has been slowed for years, according to many industry experts, some of whom spoke off the record due to the issue's sensitivity.
A tangle of patent-infringement lawsuits and threats against molders to pay hefty equipment licensing fees — as much as $50,000 per license — have been the primary reasons, they say.
Today, talk is still about patents and licenses. Some newer firms have emerged to warm the debate and claim ownership of technology.
Even so, say many experts, molders are starting to move up the learning curve and embrace new applications. Gas assist could someday fulfill its promise of more than a decade ago.
``We're still in the infancy with the technology,'' said Tom Simon, sales and marketing director of injection molder Consolidated Metco Inc. Plastics Division in Bryson City, N.C. ``There's not such a concern anymore about lawsuits. We now use it a lot on heavy-truck applications.''
But patent issues have stalled some of that focus, said Michael Caropreso, a low-pressure molding consultant with Caropreso Associates Inc. in Chester, Mass. In the past, some gas-assist molders had kept a lower profile, some working in secrecy, to fend off licensing threats, he said.
``I was hoping the [threats] would be over by now,'' Caropreso said. ``But still, more molders are licensing and practicing the technology.''
As has been the case over gas assist's history, that optimism still might be a tad preliminary. New applications are coming, but so are new patent issues.
In the past, both new applications and patent lawsuits have involved Michael Ladney. Ladney, 81, retired at the end of April from day-to-day operations at his Sterling Heights, Mich., company, Gain Technologies Inc.
Yet he vowed to continue the enforcement of the patents, even from his new home in Naples, Fla. Gain, a gas-assist pioneer, has sold licenses for gas units to 150 companies, he said.
``I'll still be in the patent picture,'' Ladney said during an April 22 interview. ``We've done a lot of the initial legwork, and we own a lot of patents.''
Ladney said he must protect his intellectual property rights, even though he sometimes is criticized by competitors for that.
Gain recorded a recent win in patent protection, Ladney said. The firm, and inventor James Hendry of Gain, had asked the U.S. Patent & Trademark Office to re-examine a 1975 Japanese patent for a sandwich molding process in an attempt to strengthen Gain's patent, Ladney said.
The patent involves overflow wells, or using gas pressure to evacuate the internal resin from the gas channel to outside the mold cavity. The Patent & Trademark Office said the Japanese patents had no influence on Gain's patented overflow technology, Ladney said.
Now, Gain can thwart attempts by other suppliers in North America and Japan from selling gas units for use with unlicensed overflow wells in the mold, he said.
Another gas-assist pioneer, Cinpres Ltd. of Tamworth, England, has battled tooth and nail against Gain for more than a decade over intellectual property rights, including spillover patents. The firms still are facing off in court.
Cinpres Managing Director Steven Jordan said the courtroom dramatics have created a Pandora's box among molders. When they open the latch and start using gas assist, they do not know what legal problems could ensue.
Cinpres, like other equipment suppliers, recently began attempting to ease the timidness among customers by offering counseling on patent questions. By getting involved early in the process, suppliers can help designers avoid potential infringements, he said.
``It's an exciting process, and we want molders to open their eyes to new uses,'' Jordan said in an April 20 interview at Structural Plastics '99 in Boston.
Meanwhile, two other firms, Epcon Gas Systems Inc. and Nitrojection Corp., are putting more logs on the patent fire. Epcon, of Troy, Mich., is suing Bauer for violating a patent that Epcon licensed from inventor Norman Loren of Warren, Mich. The patent involves pressure profiling, or stepping gas pressure up and down during molding. That case is expected to be heard next spring.
``Thomas Jefferson came up with patents for a reason,'' Epcon President Jon Erikson said. ``They protect inventors from getting ripped off.''
But he also said that Epson's lawsuit, unlike Ladney's cases, will not involve his customers. ``It's just among us girls,'' he said, referring to equipment suppliers. ``We want to see if our patent is any good.''
Gas assist should not become a commodity technology available anywhere at a reduced price, Erikson said. That will stem training, an important area for the industry's growth.
Yet, Erikson also could ask equipment suppliers to pay a license for profiling, a technique used on many applications. That could drive prices up and force some competitors out, other suppliers said.
Michael Lynch, Bauer plastic technology group manager, said all molders should be able to afford the advantages offered by gas assist without paying high licensing fees.
The Loren patent, now licensed to Epcon, is invalid and unenforceable, Lynch said. It should be in the public domain for all to use, he said.
``The misconception that licensing is mandatory has continued to stifle the growth of gas-assist molding,'' Lynch said. ``Eventually, it will blow up in court.''
The licensing problem here has skewed the market, he said. Of the number of gas-assist units sold worldwide, the North American market is smaller than both Europe and Asia, he said.
On another front, Nitrojection of Middlefield, Ohio, unearthed nine patents once owned by the company but licensed nearly a decade ago to molder Automotive Plastics Technology Inc. The molder was sold to Becker Group Inc. in 1992, and Becker was sold to Johnson Controls Inc. last year.
JCI agreed to give the patents back to Nitrojection this winter, said Steven Johnson, Nitrojection marketing vice president. The licensing agreement with Automotive Plastics had been canceled before the sale to Becker, but Nitrojection hadn't discovered that until recently.
Now, Nitrojection is offering two new, patented valve products, one for a coinjection unit and the other a fast-acting, pre-stage valve. The firm plans to protect its property rights by reviewing competitors' products, Johnson said.
Meanwhile, according to sources, the industry is growing almost in spite of itself.
If the still-sticky issues ever get resolved, many equipment suppliers, including Jordan at Cinpres, expect a 10-20 percent growth in gas-assist technology each year during the next decade.
New applications have cropped up for thinner-walled parts, for parts that require flatness, and for those with surface imperfections or in need of stress relief.
``The learning curve is much shorter now,'' said Thomas Betts, product manager for advanced processes with equipment supplier Battenfeld of America Inc. in West Warwick, R.I. ``A molder still must be willing to pay a premium for gas assist, but our customers have an easier time justifying the cost.''
New applications are found all over. For instance, Delphi Packard Electric Systems, a unit of Delphi Automotive Systems of Warren, Ohio, has started using gas assist for a press fit layer, an electrical circuit-board housing made from thin-wall, glass-filled polybutylene terephthalate. The two plastic plates sandwich stamped-metal terminals and electrical strips under a vehicle's hood.
The firm has cut cycle times, machine-clamp tonnage and tooling costs by using a gas-assist unit to make the plastic plates, said Charles Mansfield, Delphi Packard supervisor of manufacturing engineering.
Now, Delphi Packard plans to test the technology with other electrical components, added manufacturing engineer Robert Beesley. Getting over initial uncertainty has given Delphi confidence to forge ahead, he said.
With Ladney's exit from Gain's operations, that firm now is under the direction of General Manager Dennis Paul and Chief Financial Officer James Teasdale. Gain plans to challenge molders to look for new applications, Paul said.
Those could include some of the more complex parts where gas assist could work efficiently and at a lower cost than conventional injection molding.
``There will be a lull in the growth of traditional, easy applications for gas-assist, such as thicker parts,'' Paul said. ``We'd rather move from those `gimme' applications to ones that molders may be more reluctant to use with the technology.''
The cautious growth in gas assist's past was good for the industry: It gave time for the technology to develop and for firms to understand its full potential, he said.
Other suppliers have bridged countries to get the technology moving. In December, Gas Injection Ltd. of Nantwich, England, signed a licensing agreement with hot-runner manufacturer Incoe Corp. of Troy to sell its gas-assist technology in North America.
The firms hope to capitalize on some of the benefits carved by gas-assist technology in Europe and apply them in North America, said Gas Injection Chairman Terry Pearson.
``In America, they've taken the approach that big is beautiful for gas assist,'' he said. ``We think it is doable for other parts, too.''
Processors still must perform due diligence themselves to evaluate whether a license is needed, Pearson said. Still, the cautiousness from molders has hampered research and development with gas assist, Bauer's Lynch said.
``If the players resolve those legal issues, about 50 percent of injection molders could someday be using gas assist instead of 4-6 percent,'' he said. ``Once it starts to be developed, you'll see a lot of molders asking, `My God, why didn't I try this before?'''