Not all rubber is the same. More than new 10,000 compounds are created every year in Fred Waldner's laboratory. Only the very best ones end up in Continental’s tyres.
Raw natural rubber arrives in large brown bales from the rubber plantations in Thailand, Indonesia, and Malaysia. At the Continental Research and Development Centre in Hanover, Fred Waldner and his team turn this raw material into sophisticated rubber compounds for vehicle tyres, using innovative and ever more refined formulas. More than 1,500 ingredients are stored in the shelves and cupboards in the compounding laboratory, waiting to be used: both natural and synthetic rubber in different qualities, filler materials such as carbon black or silica, antioxidants and processing aids, oils and resins as well as various vulcanization chemicals.
There are at least ten different components in any one rubber compound, sometimes even as many as twenty. The formulas are created by material development colleagues. Waldner's team produces the compounds on a laboratory scale first, then the samples are tested using every trick in the book. Every rubber compound is designed for a specific spot in a specific tyre type. Only two dozen of the 12,000 samples produced and put through their paces every year by Waldner's laboratory actually end up in tyres.
One of the most ingenious inventions by the material researchers recently presented Waldner's team with a special challenge: natural rubber that is not gained from rubber trees but rather from the sap of dandelion roots. "Instead of in large bales, the dandelion rubber arrived in nuggets about 2 to 3 centimeters in size, floating in a bucket of water," recalls Fred Waldner with a smile. Even when dried, the material was so soft that it brought the mixer to a standstill. "It simply flowed everywhere!" Nevertheless, the laboratory managed to make good rubber out of it. Since then, the first dandelion rubber tyres are being tested at the Contidrom test tracks near Hanover.
A science in itself
Fred Waldner worked for many years as a material developer for truck treads at Continental before he moved to the field of physical material testing five years ago. "Rubber is one of the most exciting materials around," explains Waldner, who holds a doctorate in chemistry. "It can be molded in three dimensions in its basic state. After vulcanization it becomes elastic, can be elongated, and then returns to its original shape. And the rubber can have a more resilient or more energy-absorbing effect, depending on the material composition." In other words, the right compound has a major influence on tyre functions. On braking performance, for example, which should be as high as possible to increase safety; or on rolling resistance, which should be as low as possible to reduce fuel consumption.
Fred Waldner is a rubber enthusiast in his spare time, too. The 43-year-old is an ardent table-tennis player – "a real high-tech sport," as he says. There are 150 different rubber coatings for the rackets, all of which are different to play with: "It's a science in itself." And one that Continental will be contributing to in the near future. The company has agreed to cooperate with a large coating manufacturer on developing a new material. It won't be long before we are hearing: game, set, and match – with Conti!