Used tires often find their way to the bottom of a ravine, in a river, or slowly decaying inside a dump. However, using a retreading process can repurpose old tires, making them as good as new.
Retread, or otherwise known as a ‘recap’ or ‘remold’ is a process that manufacturers use to replace the worn out tread on used tires. Naturally, tires are incredibly expensive, hundreds of dollars at least to replace. Before retreading became an option, the only way to fix an expanded tire was to throw it in the dump and buy a new set. Retreading a tire can save upwards of about 80% compared to replacing an entire set- very attractive savings for any vehicle owner.
The process works by first inspecting the tires for signs of significant damage such as cracks and corrosion. The tires must then be ground down until the surface is completely smooth. The tires are then balanced to ensure the ride is smooth. A great deviance in weight distribution will cause the car to rattle, and in extreme cases can cause components to fail and result in damaged parts or a crash. After being thoroughly checked, a rubber coating is adhered to the outside. A technician is used to ensure the tire is a good fit and is not damaged beyond repair. Rollers are used to help the adhesion process. In the case of a remolding, once a new layer is set on top, the tire is placed inside a small oven apparatus that heats the tread up and presses in the new tread shape.
A major concern for retreaded tires is the very real concern that the retreaded layer may peel off of the original structure. Such a failure can lead to a devastating crash. Companies minimize this worry by integrating steel cables around the outside to ensure the tires will not come apart.
[Image Source: Crooked Brain]