I recently had the chance to visit Kal Tire’s OTR Tire Retread & Repair facility and their devulcanization facility in Oshawa, Ontario. I was met there by Darryl Moore, Director, Business Development Remanufacturing and Sustainability Solutions, Jon Corey, Retread Facility Manager, and Paresh Kulkarni, Devulcanization Facility Manager.

In addition to Kal Tire’s Bandag commercial truck retread facilities throughout Canada, Kal Tire also has two OTR retread and repair facilities in Canada; the one in Oshawa that I visited and one in western Canada in Kamloops, British Columbia, in addition to 4 other OTR repair facilities.

The thirty team members at the Oshawa retread facility work two shifts to produce more than 2,000 OTR retreads per year and process a roughly equivalent number of repair-only tires.

We walked through the retread process from start to finish and of course, began at the critical initial inspection phase. The experienced team members who work in this section carefully inspect every tire that comes into the facility to determine whether it can be repaired or retreaded. Depending on the size of the tires and the locations the tires are coming from, it can take up to three days to inspect 40 to 50 tires. A mistake at this stage of the process can lead to hours of lost productivity for the facility, especially if a tire starts going through the retread process and is later determined not to be a good candidate for retreading. It’s an important point to stress about retreading… only carefully inspected tires that pass quality control measures go into the retreading process. Quality in equals quality out.

At this stage, Kal Tire also removes any previous patches installed so they can re-install the patches and ensure they meet Kal Tire’s specifications for repairs.

From here, we move on to the buffing and regrooving stations where the expired tread is first peeled off in larger pieces and then the tire carcass is buffed to the appropriate texture for retreading. Again, depending on the size of the tire, the buffing process can take an average of 30 minutes, while regrooving tires can take up to 90 minutes. As we’ll see later, Kal Tire is very focused on sustainability, and they use a closed-loop tower collection system that captures all the peeled rubber and buffings to be recycled.

Next, it’s on to skiving which can also be a productivity challenge given the amount of manual labor required to skive out damage to the tires to prepare them for repair. Three full-time team members work each shift and skive between 1 and 6 tires per day. This is just one other indicator of the amount of skilled labor that goes into each of these tires during the retread process.

As we move on to the repair section, the well-trained and experienced team members carefully make repairs, install new patches, and fill skives in final preparation for the repairs either being cured and the tires returned to service or getting prepped to be built and put into molds/chambers for retreading.

It’s important to note here that Kal Tire uses 25% reclaimed rubber in their compound formulations for their use in OTR retreading. This reclaimed rubber comes directly from the capture of buffings and other used rubber from Kal Tire’s retread facilities.

Finally, the tires move on to the curing phase of the retread process. The curing chambers in Oshawa can handle tires up to 57 inches in diameter and can take up to six hours to cure.

Now we move across the street from the retread plant to the devulcanization facility and on from rebuilding tires to reusing rubber buffings in the production of tread rubber.

Becoming operational in January 2024, the devulcanization line is the most advanced fully-operable devulcanization facility in North America. Kal Tire’s partnership with Tyromer (who owns the Intellectual Property for the devulcanization process) has allowed them to recycle their retread buffings back into the tread rubber for their OTR retreads.

Commercial truck tire buffings are collected from Kal Tire’s various Bandag retread facilities and delivered to the devulcanization facility in Oshawa.

Non-contaminated rubber is critical to the devulcanization process and the buffings go through several cleaning and separation steps before moving on to devulcanization. First, the rubber buffings are fed through a magnetic drum that pulls out any metal contaminants and grinds the rubber from 4 to 10 mesh down to 14 to 30 mesh. The buffings are then run through a gravity separator and re-fed through the grinder as needed to get to the perfect mesh size. After this, the buffings are run through a de-stoning machine that separates any tiny rocks or gravel that have survived the grinding process.

The buffings are then collected in 2,000-pound bags and transferred to the devulcanization and extruder equipment located in a separate building. Using carbon dioxide, heat, and pressure, the rubber is devulcanized and the various component outputs are collected, including the now-devulcanized rubber which is extruded, passed through a second rock cleaning process, water-cooled, run through a dryer drum, applied with protective film, and cut to the correct length.

As a final quality check, the material is run through a metal detector one last time to detect any stray contaminants before being shipped to their rubber compounder, Air Boss. This devulcanized rubber then goes into the tread rubber manufacturing process for materials that Air Boss will ship to Kal Tire.

Kal Tire has been testing the use of recycled rubber in their compounds for OTR retreads and they have six years of positive experience starting at 3% of the tread rubber being comprised of reclaimed rubber. They recently upped that percentage to 25% and are having the same positive results. 

We’ve only scratched the surface of Kal Tire’s focus on sustainability. In addition to their in-house efforts to reduce their carbon footprint, Kal Tire’s Mining Tire Group has also developed a thermal conversion recycling solution for mining tires in Chile, which supports a circular economy. They have also created their unique Maple Program which provides mining customers with validated data on carbon emissions savings that can be used in environmental reporting when they choose to retread or repair a tire vs buying a new one. 

It was so fascinating to see Kal Tire’s efforts to date and I look forward to their developments in 2025 and beyond. 

The original resource is from: TRIB’s Website