Abstract
Keywords - Tires, retreading, regulation, static stiffness, infrared.
Abstract - The necessity to more exactly determine the structural conditions of used tires and, therefore, its aptitude to be retreaded by the manufacturers, has lead us to consider the establishment of a methodology in order to evaluate the tires retreading capabilities and, whats more, their new conditions for service (loading rate and speed category).
The methodology we propose in this study lies on the selection of two samples of new tires - but not used, which we shall select for a further different study of certain dimensions and trademark, that will enable us to set the parameters which are present and be sure that all samples will have the same state of usage. Previously to testing load and speed, as well as after the test, we shall evaluate the tires static stiffness. During the load and speed test, we shall register the temperatures distribution along the tire tread pattern by means of a thermal infrared camera.
Prosecuting with the process, we retread both samples, one of them according to a called cold retreading process by applying a previously stamped band over a tire already buffed and, afterwards, submitting it to a curing operation and the other tire according to the so called hot retreading process which lies on the application of rubber over the buffing surface and, after that, its introduction into a press for the curing operation. The test process is similar to the one previously mentioned, as we want to determine the tires static stiffness before and after the loading and speed test as well as the temperatures distribution occurred along the tread pattern during such loading and speed test. Finally, we analyse the results obtained in order to evaluate the main differences appeared and, afterwards, a comparative study shall be effected by testing tires of different trademarks.
Although retreaded tires may at present accomplish the requirements specified by different
Genevas Regulations, the application and validity of the above mentioned methodology will enable, furthermore, the retreaded tires manufacturers to reach higher quality standards on their own manufacturing procedures which will enable them to supply a product in the best conditions to the final user, and according to specific ranges of service.