Michelin claims to re-invent truck tyre, invests € 400 million

Ladoux, France -- Michelin claims that it has re-written the rule book on truck tyres. In the short term, the innovation appears to be centred around new sipe designs and a variation of the jointless band applied to truck tyres. The company says these two technologies -- collectively dubbed "Michelin Durable Technologies" open a new era in the global truck industry.

The Michelin Group is going to invest € 400 million over five years in order to deploy Michelin Durable Technologies across its truck tyre range. According to a Michelin spokesman, "this is just the start" Michelin will explore how the new technologies can be applied to many different tyres across the entire sector in the coming years.

The two key developments include three-dimensional moulding and a jointless band dubbed the "Infinicoil".

In terms of sipe design, the company has developed three-dimensional sipes, which are claimed to give better grip in the wet and on snow, and to improve overall life. The three-dimensional geometry has two aspects. First, each sipe has two wave geometries: one is tangential, as normal, the other radial. Michelin says this gives much greater stability to the tread blocks, offering improved grip and longer life.

The second three-dimensional aspect is a hole "drilled" across the base of each sipe. The hole is claimed to improve grip as the tread depth approaches the end of its life time. While Michelin claims the holes are drilled, they appear to be moulded. A spokesman confirmed this fact.

The breakthrough came, said Michelin, in terms of first its ability to numerically model the tearing forces on the rubber as the tyre is extracted from the moulds with re-entrant features, and second on developing a technology capable of pulling the mould segments off the tyre, against huge forces keeping the sipes and teardrop shapes buried within the tread pattern. Michelin said this process is patented, but declined to give further details.

The company says the 3-D tread blocks improve mileage, grip, payload, and load capacity by up to 50% compared to traditional solutions, especially on drive tyres. The company also changed the compound, said the spokesman. The Michelin XDN 2 Grip tyre, just launched is the first tyre to use Michelin Durable Technologies” regenerating tread design.

Michelin describes the second innovation -- a jointless band -- as 'Infinicoil', saying, "The new Michelin tyre architecture including Infinicoil technology, is made out of a giant continuous steel cord wound around the rolling circumference, which if unwound, would measure up to 400 meteres long.

"This new architecture assures optimised rolling circumference rigidity, and a level of resistance never achieved until this day. Because the tyre architecture is more robust, new dimensions of tyres can be made wider and with smaller diameters and longer lifespan."

This allows Michelin to reduce the rolling height of the tyres, while keeping carcass rigidity and so allow for lower floors in trucks, delivering greater loadspace in trucks limited by a 4m height restriction, in force on many European roads. The trend, said Michelin, is for tyre height to reduce still further as time goes on.