In the early 1990s, the American Retreaders Association, which preceded ITRA, believed that hands-on training led by an experienced instructor was the best way to teach what was then a much more manual retread process.
 - Photo courtesy Kevin Rohlwing

In the early 1990s, the American Retreaders Association, which preceded ITRA, believed that hands-on training led by an experienced instructor was the best way to teach what was then a much more manual retread process.

Photo courtesy Kevin Rohlwing

This year marked my 37th in the tire industry. I started at age 15, stacking tires when I wasn’t cleaning whitewalls at our family tire dealership. By the time I was 18, I was running road service calls all over the Chicagoland area.

Just a few years later, the service manager position at our dealership opened up, and my whole life changed. Suddenly I had the responsibility of keeping service trucks, salesmen, and three bays running and profitable every day. Then in 1996, I joined the old International Tire & Rubber Association (ITRA) as the new director of commercial tire service.

Retreading required a lot of effort in the 1990s. It was a physically demanding job that required a high level of skill. Some equipment and machines made the process a little easier or a little faster, but the human element still played a major role in the quality and performance of each retread.

Retreading required a lot of effort in the 1990s. It was a physically demanding job that required a high level of skill.

You could have five different retreaders using the exact same process and get five different results. Good people in good plants made good retreads, average people in average plants made average retreads, and low-cost retreaders typically produced low-cost retreads.

Computerized buffers were probably the first major technological achievement for the industry. Automatic computer buffers did a much better job while lowering cost and improving the performance of end products.

The reliability of retreads also has increased tremendously with shearography inspection technology. By detecting movement between the belts and belt edges, the retreader can definitively reject a casing with the pictures to show why it wasn’t retreaded. Allowable guidelines are established and the machine provides the information that either falls within or outside those guidelines. With a more stable casing, the benefits are easier to realize because fewer retreads will fail in service.

This '90s trainee was so proud of her retread that she wanted her own picture with it.
 - Photo courtesy Kevin Rohlwing

This '90s trainee was so proud of her retread that she wanted her own picture with it.

Photo courtesy Kevin Rohlwing

With the growth in automation, computerization and advanced inspection technologies, the need for skilled retread plant workers started to decrease. In 1996, most of the retread plant workers in North America were still craftsmen, to some degree. Now workers let the machines do most of the work.

How Retreading Has Changed

To say retreading has changed over the last 23 years is an understatement. There were probably 2,000 to 3,000 retread plants producing 15 million to 16 million retreads a year back then. Annual retread production has stayed relatively the same, with a slight drop to the current 14 million to 15 million-unit range, but the number of plants has dwindled to less than 800. Combine continued consolidation with more production improvements, and you are going to get a growing number of plants that retread more than 1,000 tires a day, which was unheard of back in the mid-1990’s.

This is a classic example of a student in the 1990s “eyeballing” the tread to see if it is centered and straight on the casing during the precure building process.
 - Photo courtesy Kevin Rohlwing

This is a classic example of a student in the 1990s “eyeballing” the tread to see if it is centered and straight on the casing during the precure building process.

Photo courtesy Kevin Rohlwing

Retreading today is as modern of a manufacturing process as you will see, and I believe technology is only going to get better.

The other side of the business is the industry itself. I’ve always said that marketing and giveaways sell passenger and light truck tires, while math sells commercial truck tires. For a lot of fleets, it’s cost versus price. With most wheel positions on the cost side, tire and retread manufacturers must continue to deliver the best cost-per-mile in order to compete. I believe that the economic advantages to retreading will become harder to ignore as new truck tire raw material and manufacturing costs continue to rise.

Because technology will continue to play a major role in the evolution of retreads and the retreading process, I reached out to Edd Burleson, the president of Central Marketing Inc. in Colonial Heights, Virginia, and a member of the Tread Rubber and Tire Repair Material Manufacturers’ Group, for his thoughts on retreading equipment. Burleson was a pioneer in bringing automated retread technology from Europe to the North American market in the early 1990s.

“Retreading advances are a little like Thomas Jefferson, not inventing things but continuing to improve existing things," he said.

I asked him to weigh in on the ways retreading equipment has changed and will continue to change:

On inspection: “I feel shearography is a major technological advance that has become affordable at the retreading level. Today, these systems offer bead-to-bead inspection with automatic grading of the casing based on the parameters given for each tire. The grading can split the tire into zones so different parameters can be used in different zones. Also, 3D mapping of the tire is now available, which makes the results more understandable for the operator.”

On buffing: “We installed our first computer buffer in 1994, and if we compare what we have today to what we had then, the advancements in this technology are unbelievable. The latest innovations include automatically profiling the tire and calculating all the parameters needed to buff the casing. Also, the machine will automatically adjust the buff profile to a set distance over the steel belt, adjusting each section of the tire and making sure the shoulder circumferences are the same. In addition to technology advances, there are also productivity improvements with twin hub buffers, so mounting, inflating, demounting and deflation time is reduced.”

On AZ Cushion Applicators: “This is one of the machines that has had a major impact on the industry. The AZ machine has improved quality and saved waste from cutting the sides of calendared cushion off to fit the casing, plus filling the skives. Normal improvements have been many, including decreasing cycle time, but the latest advance is the automatic setting of the wing formers with a laser camera to gauge the thickness of the cushion applied to the casing.”

On building: “This involves different types of machines, as there are different systems being used in the industry today, so they need to be addressed separately.

  • Precure. “Major improvements have been in the areas of tread pattern matching and tread tensioning that improves balance. These machines measure the tire circumference and measure the correct tread length to apply at an even tension with a splice that matches the tread pattern.”
  • Spliceless. “This type of tread is cured in one piece so there is no splice, providing an optimal amount of tension with no need for a tread match.”
  • Mold cure. “There are new extruder builders that automatically measure the casing and apply the correct amount of rubber based on the exact mold for the retread. Also, new extruders can extrude tougher rubber compounds that are required to be competitive in today’s retreading industry.”

On curing: “We still cure tires the same way by using a chamber or a press for mold cure, but there have been many improvements that have resulted in shorter cure times, with automatic controls that alert and prevent improper cures.”

On final inspection: “The major change in this area is technology that can quickly and efficiently inflate the retreaded tire to operating pressure and check it for any quality issues before the tires leave the retread plant.”

No matter how future products or services are delivered, there is a strong likelihood they will depend on vehicles with tires. In an age where e-commerce is exploding, the Transportation Research Board estimated that the number of city truck trips may double by 2022.

In many cases, tires on these urban delivery trucks may have a higher degree of retreadability. As more of them are needed to solve the challenge of the “final 50 feet,” it could mean more use of retreads.

Kevin Rohlwing is the Tire Industry Association’s senior vice president of training. A longer version of this article appeared in HDT sister publication Modern Tire Dealer.

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