LADOUX, France (Oct. 24, 2005) — Group Michelin has achieved a series of truck tire design innovations it claims allow it to accelerate the development of lower profile tires that offer greater tread stability and wet weather traction while permitting truckers to increase payloads.
Michelin will invest $480 million over five years to deploy its “Michelin Durable Technologies” in its truck tire manufacturing network, the firm said at press conference at its technical center in Ladoux. At the same time, spokesmen said, Michelin will start exploring how the new technologies can be applied to many different tires in the coming years.
The key developments of “Durable Technologies” include a jointless steel band dubbed “Infinicoil” that wraps circumferentially around the tire and three-dimensional siping.
The Infinicoil is a jointless band of steel cord—1,320 feet long if unwound—wrapped around the tire on top of the standard steel belts. Michelin claims this new architecture optimizes rolling circumference rigidity to an extent the firm believes it can make a new generation of tires that will be wider and in smaller diameters than thought possible.
This development will allow Michelin to reduce the rolling height of the tires and thus permit lower floors in trucks for greater loading capacity, especially in Europe, where many delivery vehicles' height is limited to 13 feet.
The new sipe design—which allows each sipe to have both tangential and radial wave geometries—enhances tread block stability, leading to improved grip and longer life, Michelin said.
In addition, each sipe has a reservoir molded into its base, which aids in water evacuation and enhanced wet traction as the tread wears away. This development is possible because of breakthroughs in rubber behavior modeling, Michelin said, which allows it to remove the tires from the mold without tearing the complex sipes. The process is patented, but Michelin declined to give further details.
Michelin said the 3-D tread blocks improve mileage, grip, payload and load capacity by up to 50 percent compared with traditional solutions, especially on drive tires.
The first tire to use the technologies is the XDN 2 Grip, which Michelin just launched in Europe.