Dunlop Falken Tyres Develops Tire 97% Made of Non-Petroleum Natural Materials

Dunlop Falken Tires Ltd (head office: Tokyo) of the Sumitomo Rubber Group unveiled "ENASAVE 97" at the 40th Tokyo Motor Show 2007. It is made of non-petroleum natural materials by 97%.

The tires will be released in May 2008, according to the company. The amount of petro-related materials was drastically reduced by using materials other than synthetic rubber for side walls and the inner liner.

The inner liner is a rubber sheet stuck on the inner surface of tires. It prevents the air leaking from the tire. The rubber sheet needs to be airtight. It was difficult to replace synthetic rubber with natural rubber, which is less airtight.

Because natural rubber has a molecular structure without branches on main chains, the air leaks through the material easily. The company paid attention to this point and improved airtightness of natural rubber by applying branches of epoxy radicals on its main chains.

The side walls on the sides of tires repeat distortion responding to the revolution of tires. This requires tires to be resistant to bending. Conventional material was a mixture of synthetic rubber and natural rubber, where islands of synthetic rubber are floating in the ocean of natural rubber. The islands of synthetic rubber prevented the cracks in the natural rubber ocean, realizing high resistance against bending.

If the material is replaced with natural rubber, generated cracks are likely to extend because it does not have islands. To solve this problem, the company created islands made of natural rubber and modified rubber. However, the rubbers do not blend easily. As a solution, the company blended vegetable oil and devised a mixing method.

The tread rubber is required to keep the rolling resistance low while maintaining high grip performance. The company developed a plant-derived modifier that improves flexibility of rubber. As a result, the company succeeded in creating a tire with high grip performance and low rolling resistance.

The rolling resistance is approximately 35% of "EC201," one of the general tires that contain synthetic rubber by more than 50%. The tire improves the fuel efficiency by approximately 7%, according to the company.

By increasing the rate of non-petroleum natural materials to 97%, CO2 emission during manufacturing of tires will be reduced by 17% compared with EC201. In addition, because 57% of the materials used are biomass, which absorbs CO2 in the process of growing, CO2 emission at the time of disposal will be reduced by 94% compared with tires made of petro-related materials.

Source: Tech-On, 10/26/07

Space Age inventions you probably use

When you buy a new set of tires, the old ones have to go somewhere, right? Most of them end up in huge, flammable tire dumps, which may hold millions of old tires, each one containing about a quart of oil in the rubber. If a dump catches fire, however, it can burn with a thick, toxic smoke for weeks on end.

But today, old tires are being put to good use. NASA's experience in fuel-related cryogenics helped develop processes to freeze the tires to below -200 degrees Fahrenheit so that they crumble, separating the rubber from other materials and producing what's called "crumb."

This waste is recycled into several new products, including an ingredient used to pave highways, which means your new radial tires may someday be rolling over your old ones.

Source: CNN

Do you need snow tires?

You can't beat winter tires for traction in snow and ice, but not everyone needs them, said Jennifer Stockburger, senior automotive engineer for Consumer Reports in Yonkers. Stockburger, who tests tires for Consumer Reports, talked to The Journal News about how winter tires have changed and who should buy them.

Q: What factors determine whether you need snow tires?

A: If you have a job or a responsibility that requires that you can't wait until roads are cleared, then you cannot beat the security of winter tires. They really are called winter tires now because of the temperature issue. You can't beat them for security in snow and ice.

Q: You mentioned that temperature is a factor.

A: This is where things have changed. You think about when we were kids. What they called snow tires were very luggy (with) open-tread patterns, and that was what gave them the ability to bite through snow. Today's winter tire is as much about the rubber compound as it is about the tread pattern. ... They have rubber compounds that are engineered so that when temperatures drop, the rubber stays pliable and provides better grip even on ice, whereas an all-season tire gets very stiff in very cold temperatures.

Q: How else are tires changing?

A: As cars are getting more and more capable (with) more horsepower ... the trend in original tires on cars is toward more performance-oriented tires. You can't have all this horsepower and no grip. (While performance tires have) more grip in wet and dry conditions, they give up winter traction. People are surprised sometimes. They'll say, 'Well, my old Accord was really good in the snow, but my new Accord all of a sudden isn't so great.'

Q: Often in winter, the roads are wet rather than snowy. In that instance, could an all-season tire be preferable to a winter tire?

A: Right. And that's where you as the driver need to make a determination. If you're typically leaving in the middle of the day when the sun comes out and you're on wet roads more than snow-covered or ice-covered, then an all-season's probably fine for you.

Q: What are the differences among winter tires?

A: Now there are performance winter tires as well. If you have a car like a BMW 5 Series, you have fairly grippy, very responsive tires to begin with. Now, you can buy ... performance winter models that help you maintain some of that while still giving you additional traction in snow and ice.

Q: How long do winter tires last?

A: Because they're more pliable, they will wear more quickly. ... It's one of the reasons why we definitely say you should take them off in the spring. If you do that, you can expect three or four seasons out of a set of winter tires.

Q: Some people get just two for the front wheels. Is that a good idea?

A: Never, and the reason is, you'll create an imbalance in handling. You never want one axle to be grippier than the other. ... Each tire has a brake on it. (If the front tires grip better than the rear) then your rear will tend to slide out - you'll spin out.

Source: Journal News, 10/7/07