The closer you come to the machine, the better you understand its name. When the “Hurricane Machine” is running, everything changes in the hall of the Slovakian Continental plant where it has been installed, the air seems to vibrate. The “Hurricane Machine” from Puchov is both a monster and a technical masterpiece. It rests on a deep concrete base and towers at a height of close to 15 meters, nearly touching the ceiling of the factory hall. When it starts working, you can feel the vibrations through your whole body. They come from the sheer force which rages in the large drum, the very heart of the machine.
People who do not know about this machine might find it alarming. For Martin Theusner, however, the machine’s noise is music to his ears. The doctor of chemistry devised and developed the Hurricane recycling process for Continental and to him, there is nothing sweeter than the sight and sound of it running. As early as 1996, Theusner was already giving thought to how vast amounts of non-cured steel cord waste could be recycled. At the time, he was manager of the environmental protection department for Continental Commercial Vehicle Tyres. He couldn’t understand disposing of several thousand tons of waste accumulated by Continental plants on a yearly basis at high cost, and burdening the environment somewhere with landfills.
This waste cannot be avoided in tyre production. The inability to recycle it, however, can be. After all, the material used for this is non-cured. Truck tyres contain steel cord embedded in the rubber compound, and as this rubber compound has not yet been cured, the waste in this case comes in the form of two similar types of valuable raw material. These need to be retained, conserving resources and saving landfill fees – which is ecological, useful, and also economic.
Before Theusner, no one had successfully separated the rubber compound from the steel cord on an industrial scale, in order to then recycle both components or feed them back into the production cycle. This is no easy feat. Although there are junk yards or waste disposal machines where, for example, washing machines are demolished, with metal discs dismantling the ferrous parts, a tyre compound is plastic, like modeling clay, which complicates the issue.
Nevertheless, Theusner had an idea as to how to separate the steel from the shiny black material. He had a company from Baden-Württemberg, Germany, who specialise in the construction of recycling centres, develop a special machine. Equipped with an extremely powerful engine, it has two thick upper steel chains which rotate at high speed. With several hundred revolutions per minute, these chains should now pound the steel cord waste, which is dumped into the large drum via a conveyor belt. Exposed to this constant force, the compound could become separated from the steel cord as granules. Theusner should be pleased about the success on his first attempt: “The compound granules turned out exactly how we wanted,” says the long-standing Continental employee, “and the steel cord was as clean as a whistle. This was the effect that I had very much been hoping for!”
It still took a long time before the “Hurricane Machine” came into operation. Everything was finally ready in the spring of 2012. Since then, European Continental plants have been delivering their non-cured steel cord waste to the Slovakian plant.
However, the device design did need to be further refined first. A sophisticated system for the flaps and shafts was required so that the granules and steel leave the drum at different places. During the spin cycle, talcum powder is blown into the drum to ensure the rubber granules do not stick together. They have to overcome a few more hurdles before they can be mixed again into a new tyre compound. The isolated metal, however, rolls in enormous steel wool balls in a concrete trough – valuable waste ready for selling and delivering to the steel industry. Rubber sheets, ready to be used again in tyre production.
The talcum grey granules are then sent on a journey through the Puchov factory hall. Firstly, a drum magnet separates the remaining thicker wires. However, as the smallest metal components must not stick to the inside at the end, the rubber compound is then broken down into granules in the High Gradient Separator – basically a mega magnet which sifts out all of the metal residue. And it doesn’t stop there. Before the granules are conveyed back to the regular cycle of the Continental tyre compound, Theusner sends them through an x-ray device. If there are still small bits of steel present, the affected granules are retrieved and fed through the magnet system again.
In the end, what will one day become the rubber compound of a commercial vehicle tyre trickles out through glossy chrome rollers, where it is worked over and over again in large quantities. Most of this material comes from the production process – “Waste from truck tyre production,” explains Theusner. The black material mass is now rolled and cut and rolled again before it is run in thin strips into the next roller via a conveyor belt. For more rolling, cutting, and rolling. It then travels a few more stations before the sheets, now of the quality necessary for tire production, land on pallets.
The talcum grey colour of the granules that left the “Hurricane Machine” has gone. The material, the reclaimed raw material from Martin Theusner’s recycling centre, is now completely reintegrated into the production cycle – and ready to begin a new life in new tyres!