An In-Depth Look at the Tire Retreading Process
At Bauer Built, we utilize Michelin Retread Technologies (MRT) to provide you with reliable commercial retread tires that boost fleet efficiency and protect your bottom line. Here’s an overview of Michelin’s nine-step tire retreading process, from initial to final inspection.
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Initial Tire Inspection
Our expert retread technicians conduct a thorough inspection of each tire that comes into our retread facilities. Operators are trained to spot minor external irregularities, which often indicate internal issues.
A grazing light technique identifies problem spots, and anomalies are marked on the tire tread. As the tire rotates, the technician conducts an Electronic Liner inspection to create a complete internal image of the casing’s integrity.
Buffing
This computer-automated process is managed by sensors that evaluate a tire’s structure based on insight from a database of more than 1,000 custom casing profiles.
Tires are buffed based on their brand, size and model, as well as the undertread depth and texture. The sidewalls are brushed to clean and remove contaminants.
Case Integrity Analysis
Also referred to as CIA, this portion of the retread process uses a two-step laser photography called shearography. The imaging is used to check the casing for belt separations and blisters that aren’t visible to the naked eye.
The first and second images are compared against each other to identify anomalies caused by human error.
X-Ray Inspection
The x-ray inspection provides technicians with a complete image of the steel belts inside a casing. It’s also used to check for internal problems if there’s a sidewall or bead deformity. X-rays double as an audit to eliminate guesswork and verify the tire’s integrity to ensure it’s suitable for repairs.
Repairs
A black cement adhesive agent is applied to the casing before uncured rubber patches are bonded to sections that require repairs. The technician signs each patch for application tracking and accountability. Next, the casing is sent to a curing machine that simultaneously applies heat and mechanical pressure.
Tread Building
After the necessary repairs are complete, new Michelin tire treads are applied to the casing with hot cushion gum, which is pre-molded and administered using the same machine for optimal adhesion.
That step is computer-controlled to ensure a uniform application. Cushion to Casing (CTC) technology places the cushion gum on the buffed crown and fills any inconsistencies in the casing. The retread is immediately applied to avoid contamination.
Double-Enveloping
A unique aspect of Michelin’s retread process is the use of double-enveloping to secure retreads. Interior and exterior covers create a vacuum seal around the tire to support consistent pressure and heat application during curing.
Curing
Heat derived from steam or hot water is applied to fully integrate the casing repairs and retreads. The tire is cured for 90 to 120 minutes in a computer-controlled chamber to administer consistent temperature and pressure.
Final Inspection
After the curing process is complete, the retread tires are sent to a final inspection while they’re still hot. That allows technicians to spot anomalies easier. Techs verify the integrity of the retread and double-check your specifications before sending them out for return. Some casings may go back to CIA or X-ray inspection if further internal evaluations are needed.
Retread tires offer a variety of benefits to commercial fleets. Find a Bauer Built retread facility near you and schedule your service.
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