The Incredible Tire Journey

Respect — comedian Rodney Dangerfield never received it, and neither has the tire. A tire certainly is not a beautiful object to look at, although tire manufacturers would like you to think otherwise. They try to perk up the tire’s image with sophisticated tread designs, raised white letters and glamorous ad campaigns, and some have even incorporated splashes of color into the tire making process.

But as consumers, most of us see the tire as a bland, black, round thing that is simply a necessity for our cars and trucks. Our primary concern, brought to the forefront recently with the Firestone/Ford Explorer incidents, is that tires perform their jobs reliably.

Tire buyers have to contend with S, T, V and Z ratings; 50, 60 and 70 aspect ratios; 1, 2 and 3 ply; 13-, 14-, and 15-inch sizes; 195, 200 and 205 widths; just to name a few. What does it all mean, and do you really care that your tire has all these numbers and letters on it? (There is not enough space in this article to explain tire terminology).

After comparing tires and trying to figure out if you paid a fair price, you look at your new tires, and, for an instant, marvel at the shiny sidewall that was buffed by the service technician, and admire the thick tread that now lies beneath your vehicle. In an hour, that feeling will be gone, and you may never think about your tires again for about another three years – when the time comes to buy new ones.

MAKING THE TIRE

The wheel, of course, has been around for thousands of years, but the modern, rubber tire has been in widespread use for only about 100 years. When rubber was first used to cover wheels it had problems. In the summer, the rubber would get sticky and gooey, and in the winter it would become hard as a rock.

Then the tire making process got its most significant boost when a man named Charles Goodyear discovered that when he added sulfur to rubber and heated the mixture, a consistent compound was formed that maintained its properties in extreme heat and cold. That discovery was made in 1839. Ironically, Goodyear never was able to capitalize on his product. He fell in and out of poverty, and was jailed several times for failure to pay debts. In the end, he died a poor man, owing more than $200,000. Later, the Goodyear Tire & Rubber Company would be named in his honor, although neither Charles Goodyear nor any of his direct relatives had anything to do with the formation of the company. When faced with the notion that others would make money through his discovery, Goodyear once wrote, “Life should not be estimated exclusively by the standard of dollars and cents. I am not disposed to complain that I have planted and others have gathered the fruits. A man has cause for regret only when he sows and no one reaps.”

The process of curing rubber and sulfur became know as vulcanization – heralded as the most important discovery in the tire industry to date. Until World War II, tires were made mainly from vulcanized natural rubber (some tire makers used fillers such as crushed walnut shells and other materials to help with traction), but the war effort required that natural rubber stocks be diverted. Chemists soon found ways to make synthetic rubber to fill the void for general public use, and the U.S. and other industrial nations began the long road to weaning their consumers off of tires made solely from natural rubber.

Today, while natural rubber and sulfur are still used to make tires, other ingredients such as synthetic rubber, silica, resins, oils, fabric (polyester/nylon), petroleum waxes, pigments (zinc oxide/titanium dioxide), carbon black, inert materials and steel wire are also included. In the average passenger tire, which weighs about 25 pounds, carbon black accounts for 28% of the weight of the tire, while synthetic rubber accounts for 27% and fabric (polyester, nylon and other materials) about 16%. Steel accounts for about 15% and natural rubber around only 14%. This final mix depends on the type of tire and the manufacturer.

One of the biggest misconceptions about tires is that they are made from a mold where a liquid slurry of rubber is somehow poured around steel and fabric reinforcing material. In fact, nearly all tires are built individually by workers called tire builders. The tire builder’s job is to splice together the various layers of a tire — the belts, plies, inner liner and tread rubber — as well as attach the steel beads. Once this is done on a special machine, the tire carcass is sent to a curing mold that has the tread design imprinted on the inside. The carcass is placed in the mold for a short period of time to cure and to take its final shape. Once out of the mold, the tire is trimmed, inspected and stored for shipment.

A THANKLESS LIFE

Okay, so the truth is the general public does not think about tires until or unless they fail, as with the Firestone/Ford Explorer controversy. And why should anyone? Such failures are considered so extraordinary that they make headlines. The modern tire has been a quiet workhorse under cars or trucks for some time. Today’s tire (with proper maintenance) can last up to 80,000 miles (depending on the model, driving conditions and tire care), and steel belts and self-sealing compounds make road hazards almost obsolete. New run-flat designs that can maintain tire integrity and shape when punctured are now hitting the market and promise to make driving even safer.

In addition, tire prices have also remained relatively low and stable, as mileage ratings have increased. The fact is that the tire is a better value today than it was 20, 30 and even 40 years ago. In all, the life of a tire is a thankless one. It’s never praised for its unrelenting job of keeping the car or truck safe, gripping the road in various conditions and providing added security.

DISPOSAL DYNAMICS

Now the time comes to make that painful decision to buy new tires, and before you can say “I’d rather have that root canal now on my tooth,” the purchase is made and the new tires are on and the old ones off.

Most likely, your local tire dealer charged you anywhere from 25 cents to $2 per tire for disposal. Depending on what state you live in, that fee can serve several purposes. It can help pay for scrap tire education; proper tire disposal; or to sponsor a licensing program for tire haulers.

The last one is important because there is a history in this country of unsavory tire haulers who charge a pickup fee to remove the tire from the tire dealership, and then simply find a ravine or parcel of vacant land to illegally dump them. In time, water collects in the tires making a perfect breeding ground for mosquitoes and other vermin. The tires are unsightly, and eventually a local or state environmental agency will have to incur the cleanup costs.

Since many states (plus the federal government in the form of Superfund) can hold tire dealers accountable for using bogus haulers, many tire dealers require haulers to be licensed or at least check out where their scrap tires are going.

Once picked up, scrap tires can go to one of three places: a certified tire dump, a standard landfill (in some states), or directly to a recycling facility. Tire dumps are normally sanctioned by the state, and must include proper fire lanes and other protection. Some tire dumps will shred the tires immediately on site to reduce volume and remove the threat of breeding mosquitoes and other animals.

Historically, some tire dumps became so large that state officials had to move in and close down the operations. The story line in all the cases is usually the same – there was no profitable end use for the scrap tire, so the piles just kept getting bigger.

Some of the biggest tire piles in the U.S. have been in the states that generate the most scrap tires, like New York, Texas, Ohio and California. The infamous Westley, Calif., tire pile in northern California was so big that an on-site tire-derived fuel (TDF) plant was built to convert the scrap tires into electrical power in 1987. After 13 years of burning tires to generate electricity for local homes, the plant closed in January 2000 due to nearby fire and other problems. During its operation, the plant burned more than 66 million scrap tires over its lifetime.

Another option is for the tire to go directly to a tire recycling facility. These facilities shred and crumb tires to produce a product that can be used at TDF sites, cement-making plants, in civil engineering applications and as a turf care product. TDF is the largest end market for scrap tires, and since tires are burned in this method, it is a one-time reuse.

Shredded tire fragments can be used for TDF, playground cover, daily cover for landfills and as road base material. Crumbing facilities are more intensive, as the machinery has to separate the rubber from the steel and fiber. Processors also use cryogenics to break apart tires to separate the rubber from the fiber and steel. New ways such as magnetic shock and electric pulse are being studied to disintegrate tires.

Crumb can be used as a soil additive, or in the manufacture of low-grade products, such as mats, coverings and soaker hoses. It is also used in the making of new roads as a component in asphalt mixes. Several states, including Arizona and California, have extensively used rubberized asphalt with success. These roads flex better and crack less, but early problems with poor mixtures created some roads that simply fell apart. In the end, a proposed federal mandate in the early 1990s to use scrap tire rubber as an additive in asphalt was rejected, and each state currently is on its own to develop and use rubberized asphalt.

Some operators have even tried to break scrap tires down in a pyrolytic process (heat without oxygen) that creates tire ash, low-grade diesel oil, fiber fluff and steel. Although operators have tried to make this process work, there are currently no known pyrolysis plants commercially operating in the U.S.

Retreading is also considered a form of recycling. Passenger tire retreading in the U.S. is a small industry. However, truck tire retreading is still a large part of that market. The reason why is that truck tires are high-cost items, and retreaders can remain viable with an alternative quality product that is price competitive.

The biggest buzz in the tire recycling industry for the past five or more years concerns de-vulcanizing processes. These processes vow to break the strong sulfur-rubber bond that forms during vulcanization. At first these processes were de-bunked as phony, but now companies such as Michelin and Goodyear have publicly announced that some level of de-vulcanization can indeed occur. What this means is that de-vulcanized rubber from scrap tires could eventually work its way back into the manufacturing of new tires – the ultimate recycling scenario. This is the area that holds the most promise for scrap tires, as about 250 to 270 million new tires are made each year in the U.S.

But according to a Goodyear representative, the use of de-vulcanized rubber in new tires is still not a perfected process, and may take some time to iron out all the difficulties before a significant amount of scrap tire rubber can be used to make new tires.

The bottom line is that scrap tires are used in a wide variety of secondary applications. The bad news is that many of these operations are not profitable or are just breaking even. One tire recycler called me from jail several years ago, and insisted that he was a good man who tried to make tire recycling work. Over time, he found that the tires kept coming into his recycling business, but hardly any were going out to markets. After being cited several times by local authorities for lack of fire lanes and too many tires on site, he was jailed and eventually lost his business and his house. That may be a dramatic case, but failed tire recycling ventures are not rare occurrences. Just recently, a facility in California was fined $225,000 for improper tire processing and storage.

So why is it so hard to make a buck recycling tires? The main reason is that a tire is constructed to last. Therefore, it takes a tough shredding machine to rip it apart. The other reason is that a tire is made from so many different compounds and materials. The tire can have one type of polymer in the tread, and another in the sidewall. Plus, the fiber and steel has to be separated for crumbing operations.

Still, there are numerous examples in the industry of tire recycling companies that have bucked this fatal trend, and which have survived and are profitable. Among the points to consider when entering the tire recycling field are these: (1) Be extra cautious of too-good-to-be-true claims; (2) Do your research thoroughly; (3) Charge adequate tipping fees to cover your recycling costs; (4) Have a real market for your end product; and (5) Have plenty of capital.

In short, manufacturers have done a good job at making the modern tire, finding an equally reliable way of de-constructing them for recycling has proven elusive.

Mark Phillips is a former managing editor of Recycling Today and Tire Review. He can be reached via e-mail at mdphillips@core.com.