DUSSELDORF, GERMANY-While European automakers are making incremental advances in auto-motive recycling, their primary efforts continue to focus on design for disassembly and developing efficient ways to recycle shredder fluff. Progress in those areas continues to be slow. In talks delivered Oct. 4 in Dusseldorf at Autoplas '95, spokesmen for automakers provided details on their efforts to develop technologies to recycle cars and shredder fluff. The spokesmen represented: Regie Nationale des Usines Renault SA of Boulogne, France; Nissan European Technology Centre (Brussels) SA, the European technology unit of Nissan Motor Co. Ltd. of Tokyo; Daimler-Benz AG of Stuttgart, Germany; and Deutsche Automobilgesellschaft - the Braunschweig, Germany-based automotive recycling consortium known by its acronym, DAUG.
European automakers are advancing recycling technologies to address legislation that mandates increased proportions of cars be recycled over the next 10 years.
No European automaker has found a solution to the elementary problem posed by recycling, said Hans-Rainer Lotz, DAUG spokesman and director of recycling for Mercedes-Benz AG of Stuttgart, a subsidiary of Daimler-Benz.
``The increasing amounts of plastics used in cars and the increasing number of cars, themselves, cause problems as a high amount of shredder dust when today's [recycling] technology is used,'' Lotz said.
``High operating and personnel costs will always be a problem. New concepts, like the dismantling of plastic parts, are urgently needed'' to develop ways to reduce automotive shredder fluff, Lotz said.
As it stands, 75 percent of the materials from used, post-consumer vehicles in Europe is recycled, and the remaining 25 percent is mainly disposed of in landfills, said Emmanuel Humbeeck, an engineer with Nissan European Technology Centre.
Humbeeck noted that auto-makers are pursuing three forms of recycling: material and chemical recycling, and waste-to-energy incineration. He said Nissan's efforts have shown material recycling can be much more expensive than chemical recycling or waste-to-energy incineration.
Humbeeck said those three methods have to be used in balance to provide an effective and economic recycling program.
He gave details about Nissan's development of a new technology to recycle plastic fuel tanks. Fuel tanks made of two layers of high density polyethylene, two adhesive layers and a vapor-barrier layer of nylon are used in most European cars.
The new technology addresses the problem of absorption of gasoline by the inner HDPE layer. That absorption reduces the flashpoint of the material to less than 122§ F, Humbeeck said.
Nissan European Technology Centre developed a technique to shred and grind fuel tanks in an inert atmosphere, wash the ground residue, then dry the resins in a vacuum oven to remove the absorbed fuel and the moisture, Humbeeck said.
That process raises the material's flashpoint to more than 662§ F, well above the processing temperature used in the twin-screw extruder that turns the production scrap into reusable pellets, he said.
While Nissan developed that process, Renault reprocessed 85 percent of 17,000 scrapped cars in its effort to attain goals set for the French auto industry by the year 2002, said Jean-Paul Vallat, Renault's recycling operations project manager.
The 1993 French Framework Agreement set goals for everyone involved in automotive waste handling, including wreckers, shredders, producers of secondary raw materials, original equipment manufacturers and the French Ministries of Industry and the Environment.
The goals are:
To be able to recycle 85 percent of all cars by 2002.
To develop and launch cars by 2002 in which 90 percent of the materials are recyclable.
To be able to recycle 95 percent of a vehicle.
Establishing such goals has led to rationing the responsibilities for recycling, Vallat said.
Renault's efforts are mirrored at Daimler-Benz, where Martin Guldenpfennig, a research scientist, said efforts have focused on designs for removability, reprocessing, and, as the least desirable option, for disassembly.
``A design for removability is required so that entire subassemblies made of plastic compounds can be removed from the vehicle without great efforts,'' Guldenpfennig said.
With such a design, fasteners will have to be severed without being destroyed so the components themselves can be reused, he said.
``A design for disassembly is only required if - in case of repairs - subassemblies must be exchanged or disassembled quickly and without destroying them,'' he added.
After describing automotive
instrument panels as the largest and most complex automotive structure contributing to shredder fluff, Guldenpfennig said Daimler-Benz has developed techniques that can be used to recycle 86-91 percent of instrument panels.
Those techniques include crushing, glycolysis separation of some plastic resins, mechanical separation of ferrous and nonferrous metals, and further mechanical separation of ABS, PVC, glass-fiber-reinforced thermoplastics and polypropylene resins. In Daimler-Benz's laboratory process, the residual, 9-14 percent of instrument-panel products are sent to an incinerator, Guldenpfennig said.
The problem with designing car components for disassembly, Lotz said, is that his company's research has shown simple dis-
asembly yields 16 percent pure plastics for recycling, while yielding 37 percent compounds that are difficult to recycle and 47 percent of products that require further or complex disassembly to be recycled.
Pilot projects have shown it costs $190-$230 to dismantle and recycle an old car, including the costs of moving the car to a recycling station and dealing with the drainage of fluids, Lotz said.
Because of the costs and difficulties, he expects automotive recycling will continue to generate large amounts of fluff that will have to be incinerated until new technologies are developed.