The market for plastic fuel tanks is picking up again, thanks to processors' efforts to meet air-quality standards. The market trend away from steel reached a plateau a few years ago when automakers became seriously worried about the fuel permeation from high density polyethylene tanks.
``In Europe some time ago, the use of plastic fuel tanks climbed to 75 percent or 80 percent [of the automobile market]. And, even today, more and more cars there are going plastic,'' said Norman W. Johnston, president of Solvay Automotive Inc. in Troy, Mich.
In North America, however, plastics took about a 20 percent market share, then froze, Johnston said.
``The Clean Air Act came along. Peo-ple also were worried about California Air Resource Board regulations and the word went out you'd only be allowed 2 grams of emissions via the 24-hour test procedure. People began looking very closely at plastic fuel tanks and their technology,'' he said.
In Europe, Johnston said, clean-air regulation has not reached such a fever pitch and fuel diffusion through tank walls has not become a front-burner consideration.
``There are three different ways you can go to make a plastic fuel tank that doesn't have an environmental problem. That's what has broken the stagnation, and the real news is, in this country we're now back on the same ramp up that Europe's on,'' he said.
His forecast must warm the hearts of resin suppliers: ``We're back on the track where 60 percent of 15 million means 9 million plastic fuel tanks in 1998 in the United States with 18-22 pounds of HDPE per tank.''
The technologies that John-ston and others are using to prevent seepage all involve improving the barrier properties of HDPE tanks: fluorination, sulfonation, and coextrusion with materials such as ethylene vinyl alcohol or nylon. Experts say the three methods bring extremely low levels of permeation.
Gary J. Ulicny, sales and marketing manager of Kautex Corp. in Windsor, Ontario, said that plastic fuel tank maker is doing well.
``That doesn't mean we couldn't use more - we could. But business is fine,'' he said.
On a chart, sales from the company's two plants right now could be represented with a 45-degree, upward slope, Ulicny said.
``The market is going to continue to grow so that in the 1998-2000 time frame, more than 50 percent of cars built in North America will have plastic tanks. By the 1997 model year all the Chrysler vehicles will have plastic,'' he said.
Detroit observers, in discussing steel vs. HDPE, point to the huge capital investments the vehicle builders have in metal stamping plants and tank manufacturing facilities. Steel tanks are going to be around a long time, it is generally agreed.
But plastic's durability, ease of molding in odd shapes and light weight make it a serious contender.
``It's the ability to fill space, wrap around axles and arrange in chassis areas,'' Ulicny said.
An average plastic tank, the rule of thumb has it, weighs two-thirds less than an average steel tank.
Tooling for plastic tanks also is cheaper than for steel, plastics processors contend. That may be an important consideration at a time when automotive marketing executives promise with considerable regularity that low-volume niche cars are on the way.
``With emissions solved, the lack of corrosion with plastic may come to the fore. In an era of 10-year warranties, regardless of coating, the corrosion of steel is still a consideration,'' Ulicny said.
Walbro Automotive Corp. of Auburn Hills, Mich., is another player in the automotive fuel tank game. The company is a subsidiary of the publicly owned fuel storage and delivery specialist Walbro Corp. of Cass City, Mich.
The automotive arm, at a plant built in 1993 in Ossian, Ind., produces coextruded, six-layer plastic tanks. Production is on one machine blow molding the tank for the Ford front-wheel-drive Windstar minivan. That is unusual because Ford normally blow molds its own tanks at a plant in Milan, Mich.
The Ossian plant has annual capacity for 500,000 tanks, and Walbro expects to announce this quarter that it will land some more business from Big Three automakers for the 1997 model year.
Walbro has an additional Krupp-Kautex blow molding machine on order, which will increase annual capacity to 1 million units, said Walbro Corp. Chairman L.E. Althaver.
Walbro claims the distinction of producing tanks without waste. One layer of its tank is made of regrind HDPE.
``We made a fresh start in the tank business with a clean sheet of paper. We hadn't been in the business and we had no obsolete concepts or machinery,'' Althaver said.
Walbro feels the outlook for its future in the tank business is very good, Althaver said in an early January interview in Cass City. Automakers, he said, either can go back to steel and not take advantage of plastic's lightweight, relatively low tooling costs and corrosion resistance, or can pick plastic with an anti-permeation system.
Walbro expects to see plastics account for about 50 percent of the U.S. tank market in the year 2000, he said.
On Jan. 5, Walbro Automotive and Dyno Industrier AS in Oslo, Norway, announced plans for Walbro to acquire for an undisclosed amount Dyno's fuel tank division, which has six tank plants across Europe and annual sales of about $150 million.
Walbro has a joint venture based in France that produces fuel-delivery system parts that eventually become part of the fuel tank assembly. Those parts include in-tank fuel modules that combine the fuel pump with a fuel reservoir system and contain level sensors, purge valves and safety-related rollover valves.
Dyno expects to sell 1.7 million tanks this year. Significantly, none of those will go to Euro-pean operations of the U.S. Big Three, a situation Althaver expects to change.
``Walbro's connections and Dyno's capacity are what will increase our penetration,'' he said.
The Norwegian acquisition points up a trend in the auto industry. Ford and GM have told suppliers they must think on a global basis, and most auto-makers are pushing vendors to supply increasingly complex total systems rather than just parts.
``If you're not a global supplier you won't get the business as a tier-one supplier. You'll be relegated to tier two or tier three,'' Althaver said. ``If you're not a tier-one supplier, you're always going to be playing catch-up.''
Until recently, Kautex supplied tanks for Ford Motor Co.'s Explorer, but that vehicle's 1995 model was switched to steel. At the time, Ford said its engineers were not certain plastic tanks could meet the Clean Air Act'sfuture toughened emissions standards.
``We almost got there, but didn't make it. If we'd had another half-year we would have made it,'' Ulicny said.
Kautex at the time was concentrating its efforts on fluorination of tanks as a sealing technique. It has since developed a six-layer coextrusion process that can be combined with fluorination. One of those layers is ethylene vinyl alcohol.
Solvay also has tanks with an EVOH layer, but Ulicny said Kautex is the first in commercial production with the material. The EVOH layer is used on the Grand Cherokees sold in California, where vehicles must meet increasingly stringent emissions standards of the California Air Resources Board, Ulicny said.
Tanks for the strong-selling Dodge and Plymouth Neon line are of the Kautex multilayer type, he said. The company believes that by 1998 virtually all plastic tanks on new cars sold in California will have multiple layers.
In Kautex tanks, EVOH is substituted for a nylon layer used by other makers. Nylon is sensitive to alcohols of the type used in fuels, and that sensitivity can lead to decreased performance in permeation prevention, said Andreas Puempel, Kautex Corp.'s engineering manager.
A seventh, fluorinated layer is optional for improved alcohol performance, Puempel said.
The Kautex multilayer tanks with the EVOH layer were developed jointly by Kautex in Canada and in Europe, Ulicny said. Kautex is a division of Klockner-Werke AB in Duisburg, Germany.
Kautex and Solvay also pro-duce other plastic items including fuel-fill necks, seat backs, headrests, ducts for heating, ventilation and air conditioning, bumper reinforcements, filler pipes, washer bottles, load floors, and ducts that bring air to engine intake manifolds. Walbro, with 1993 sales of $273 million, injection molds fuel-system components for a range of applications, including trucks, chain saws and lawn mowers.
Solvay's Johnston chairs an industry committee that filled a void as it developed a very rigorous test for plastic fuel tanks.
``I haven't found a metal gas tank that will pass it,'' he said.
The test's components include pressure and vacuum, sloshing, dropping and extreme temperature cycling, Johnston said. Metal tanks leak through the weld line, he said.
``At the end of the day, the bottom line is, we could find several different technologies that would enable you to make a plastic fuel tank that would pass all these metal-killer tests, and you'd still be below a tenth of a gram per day in hydrocarbon emissions,'' he said.
Solvay Automotive is a subsidiary of Solvay America, in turn a unit of the Belgian giant, Solvay SA. The U.S. company has plants in South Bend, Ind., Blenheim, Ontario, and Puebla, Mexico, and a technical center in Troy. The firm also makes HDPE and has in-house capacity of about 1.5 billion pounds of pre-compounded black resin.
``Out of all the plastic fuel tanks that will be made in North America in 1996, we'll make almost half of them. We use all three technologies. We've got more than one horse in the race. I like to think we're not only right in step, but we try to stay at least a half-skip ahead,'' John-ston said.
Solvay tank customers include the Big Three and Volkswagen in North America. Recently, the company won contracts to supply HDPE gas tanks to General Motors for the Buick Riviera and Oldsmobile Aurora, and to Chrysler for the new-for-1995 Chrysler Cirrus and Dodge Stratus. There is no Plymouth version of that compact car, but one may be offered in the future.
Kautex customers for plastic fuel tanks include Chrysler for its Jeep Grand Cherokee and the Dodge and Plymouth Neon and General Motors for all the Cadillacs. Kautex received an award this year as a GM Supplier of the Year for its 1993 performance.
Kautex will be in Mexico soon as a supplier of tanks for Volkswagen's Concept 1 vehicle - a VW Beetle look-alike scheduled to go into production in Puebla for the 1998 model year.