The primary objective of tire inspection is to select tires for retreading/reparing that are free of manufacturer defects, non-repairable damage, excessive are, and to reject tires that are not capable of wearing out another tread. Therefore, inspection is a fundamental function in every retread plant.
The primary objective of tire repairing is to restore the strength and flexibility of a damaged tire within the maximum injury size limitation as periodically reviewed and published by an industry committee, repair material manufacturers and new tire manufacturers. The tire repair specialist has the responsibility of probing and analyzing an injury, its location in the tire body, its size, tire usage, etc. and making a determination if it can be safely and economically repaired.
A worn tire must be prepared in such a fashion to meet the following objectives
Remove sufficient oxidized surface rubber from the casing to receive new rubber
Achieve a surface texture to promote maximum adhesion
Shape the casing to predetermined dimensions. (Overall buff, crown radius, crown width, diameter and bead to bead dimensions.
Buff the tire to achieve maximum concentricity. ( true of balance casings)
The objective of buzz-out filling is to provide a uniform surface on which to build a retread. Areas of the buffed surface that have been cleaned out by skiving or buzz-out must be filed with cushion gum. Since the buzz-out is a minor repair, no reinforcing after cementing is required.
The main objectives of cementing are:
- Provide necessary to hold a build up unit together until it can be cured
- Provide protection to the buffed surface to prevent oxidation and vapor contamination during storage periods required in normal retread or repair operations.
- Provide sealing of cord ends in skived and buffed repair cavities.
- Improves adhesion.
6. Tread building / Tread application
The purpose of tread application is to apply the correct size tread rubber or pre vulcanized tread to a buffed and cemented tire.
7. Tubing, Rimming and Enveloping
The envelope is designed to create a differential pressure between the tread and the buffed surface of the casing. This pressure is very important to create proper bond of the tread to the casing during the curing cycle.
Both Precured and hot cure basis must be cure in a different degree, the High tech of Olympic's Curing machine ensure that the retread tire always in superior quality
9. Final Inspection
Final inspection has to be done to ensure the every retread tyres arrive to the customers hand is free of manufacturing failures.