Researchers Find a Way to Recycle Plastic Components of Dead Cars
Plastics, once they´ve been installed in a new car, rarely make it to recycling projects by the time the car’s life is over. That is because once the plastic’s compressed in granulates, the car plastics tend to be too coarse to permit further use.
Researchers have now found a way of separating the different types of plastic. In theory, any car that ends up on the junkyard is a source of raw materials. But, other than to the Picassos and practical mechanics among us, this is virtually not a proven theory by any means. The ´available´ resources are used far too seldom, especially when plastics are concerned.
So how can clever recycling put an end to this? Generally, when cars are recycled, the plastics in its interior, known also as polymers, land in the non-metallic shredder residue along with dust, slivers of metal and textile fluff, and are made into granulate using the SiCon process.
Most shredders simply jumble the plastics. But a research project sponsored by Toyota and Sicon has solved the problem of car polymeres; It is now possible to separate them into individual types. This means that most car polymeres, rather than being used in blast furnaces, will be recycled and transformed, once again, into dashboards and other car parts.
The project, also known as CreaSolv®, is researched by the Fraunhofer Institute for Process Engineering and Packaging IVV in Freising. The researchers have developed a special solvent that removes a particular type of plastic from the coarse granulate. `The polyolefins used to make air filter housings, shock absorbers and side panels,” says IVV project manager Dr. Martin Schlummer. “While this type of polymer dissolves in the solvent, the other plastics remain in the granulate.”
The project then devised a way to separate the solvent from the polyolefin so it can be re-used. The researchers also discovered another advantage, they say. The CreaSolv® process turned out so effective as a cleaner that scientists can also separate out any toxins with which the polymer may have come into contact during shredding. “Using this technology, the overall recycling rate for end-of-life cars – metals, plastics and textiles – can be increased to over 90 percent,” says Schlummer.
The researchers have conducted tests on the recovery of styrene copolymers from electrical appliances such as computers and TVs. When doing the tests over the past year, they managed to recycle about 50 percent of the high plastic content in discarded electrical appliances.
Nevertheless, a great deal of development effort was necessary before it was possible to process the plastics from cars as well. “Different polymers are used in cars than in electrical appliances, so we had to develop completely different solvents,” the expert explains.
The researchers have already put the basic process into practice. In future, they intend to recycle other types of plastic from cars in addition to the polyolefins – perhaps by combining the methods for recovering styrene copolymers and polyolefins. Eventually, Schlummer hopes, it will be possible to make optimum use even of plastics from shredding plants where refrigerators, kitchen ranges and cars are all shredded together. The ultimate challenge, for sure, would be airplanes and train compartments!