STERLING HEIGHTS, MICH. — If the gods of rigid polyurethane are smiling, a new process—creating a PU-and-fiberglass mix with the gooey look of pancake batter—will gain favor with automakers.
Three separate camps of PU resin and equipment suppliers have invested millions in developing a new technology to revive rigid PU. Once a formidable contender for both interior and exterior automotive applications, the material has taken a sideline seat in recent years to lower-cost thermoplastics.
The new process, which tweaks traditional structural reaction injection molding, could change that. If nothing else, it may be the last best chance for those suppliers to shift to a higher gear in PU applications.
``We think this will keep us in the ballgame with hard parts,'' said a hopeful Gregory Pelts, automotive commercial manager with ICI Polyurethanes in Sterling Heights. ``We've got a lot more to talk about now, and we'll have a lot more visibility because of it.''
The PU-and-glass blending process, showcased as future technology at plastics shows since 1995, is making its debut with automakers this year. Already, the process is used for the new Mercedes-Benz CLK convertible.
Suppliers expect the technique to turn the industry on its ear. Instead of having to lay a prickly piece of glass mat, essentially a thick blanket of glass, across a mold, the new technology allows long-fiberglass particles to be blended automatically with PU and poured by nozzles over the mold.
The process saves both time and irritation — glass mat is difficult to handle. And the new technique will cut down on product waste, always a difficulty with SRIM.
``Recycling is a huge issue [with PU],'' said Ken Shaner, general manager of Magna International Inc.'s Versatrim interior trim operation in Howell, Mich. ``You can chop up and reuse some of it, but not enough. And people don't like to handle pieces of glass because it's a health problem.''
But the big issue for PU suppliers is restoring market share. The material once dominated bumper fascias; now thermoplastic olefins have taken over that market. As for the interior, where suppliers expect the new process to thrive, PU use pales in comparison to thermoplastics for door panels and instrument panel skins.
All of the suppliers' solutions are similar in concept—and each supplier believes its option has the best chance to succeed.
``We invented the process three years ago, and we have the experience to do it right,'' said Glen Grosser, general manager for the Reaction Process Machinery Division of Krauss- Maffei Corp. in Florence, Ky. ``Now, others are jumping on the bandwagon.''
Equipment supplier Krauss- Maffei, working with ICI Polyurethanes, captured the first application on the Mercedes car, which is molded by Johnson Controls Inc.'s Becker Group Europe subsidiary, based in Wuppertal, Germany. Krauss-Maffei's process is called LFI, which stands for long-fiber injection.
That application, for the car's door panels, is only the tip of the iceberg, said Frank Peters, sales manager of Krauss-Maffei's office in Munich, Germany. The technology will be even larger in the United States, he said.
``North America is a classic low-density SRIM market,'' Peters said. ``Therefore, it's a good market to target the technology.''
At ICI's automotive center in Sterling Heights, a prototype LFI machine is stationed at the vortex of a production shop. It directs cut pieces of glass, called rovings, into a mix head to commingle with PU, which is automatically shot to the same chamber by metering pumps.
Robotically controlled nozzles spray the stew of PU liquid and chopped glass onto the mold in a preset, criss-crossing pattern.
Two global equipment suppliers are nipping at Krauss-Maffei's heels. Hennecke Machinery Co., a Berlingen, Germany-based unit of PU maker Bayer Corp., and Milan, Italy-based Cannon SpA, are rolling out their own chopped-fiber PU machines. Both firms say theirs are superior products in the chopped-fiber revolution.
Whatever variation makes the cut will be an advantage over existing PU techniques, said ICI business development manager Tony Cleveland. Another PU process using glass fillers, reinforced RIM, is too costly for higher-volume applications, he said. That has left PU in a difficult spot until now.
Besides the mix head and process controls, no other new equipment is needed with a standard SRIM machine. The total cost to retrofit a machine, in many cases, is less than $200,000, Grosser said.
The savings are astounding, says the ICI/Krauss-Maffei team.
It estimates that the process reduces glass costs at least 40 percent by using rovings instead of glass mat. It also claims that labor and material costs are reduced, cycle times are cut to 60 seconds from as much as 180 seconds, and flash is eliminated by removing the need for resin in cutout areas of a closed mold.
The other suppliers cite similar savings.
Hennecke's FipurTec chopped-fiber process, in development for two years, blends the PU and glass strands outside the mixing head.
Thus, air bubbles are reduced and the mix can be controlled better, said William Worms, Hennecke's Lawrence, Pa.-based director of advanced development.
The FipurTec mix is applied to a mold by a flat robotic piece.
``We call it a pancake spatula,'' Worms said. ``It gives better coverage in the mold.''
Meanwhile, Cannon's InterWet process takes the idea further by allowing more than glass to be used. The company's mixing heads can use such materials as chopped scrap foam, mineral fillers or pulverized plastic, said Lisa Shaner, sales and marketing director for Cannon USA Inc. of Cranberry Township, Pa., near Mars, Pa.
``Cannon is several steps ahead,'' Shaner said. ``We've been trying for years [as an industry] to grind up foam to make PU more recyclable, and this will help us reuse it.''
But the material still must pick a fight with thermoplastics, which are recycled more easily, said Versatrim's Ken Shaner, who is no relation to Cannon's Shaner.
Versatrim's Shaner added that injection molded ABS costs less and can be produced faster than PU. However, PU parts offer better strength and impact protection, two areas that turn suppliers' heads, he said.
``I think the chopped fibers could grow [the PU] market a little bit because of its advantages,'' he said. ``But I don't see a huge jump over thermoplastics.''
Producing a lower-density part might be the biggest selling point of the chopped-fiber PU process, said Phil Sarnacke, an auto consultant with Houston-based Phillip Townsend Associates Inc. By using thinner glass rovings, a part can achieve the same strength as with a glass mat, said ICI's Pelts.
But Sarnacke is not sold yet on its growth.
``It's certainly a good process improvement to allow urethane suppliers to go after more structural applications,'' said Sarnacke, who is based in Midland, Mich. ``But the downside is that it has another complicating processing step. It's not simple to operate with untrained technicians.''
But the chopped-fiber-process suppliers all say they have work on the way with automakers.
Krauss-Maffei will have its first North American contract with the LFI process within three years, Grosser said. Hennecke's FipurTec process will be used by a supplier in 1999, Worms said. And Cannon's Shaner said her company is developing the InterWet process with a North American auto parts supplier.
``It isn't something everyone and their brother are going to use,'' Shaner said. ``But this creates opportunities in areas we haven't been able to address before.''