Ozone ageing tests

For a number of years, Laboratoire Dubois has been conducting in-depth investigations in the field of straps and components made from elastomer (more commonly known as rubber), their characteristics and their degradation modes. Some of these works have been published ("Bulletin de la Société Suisse de Chronométrie" [Swiss Chronometry Society Bulletin] No. 55, September 2007; Actes 12e Journée d'Etude de la Société Suisse de Chronométrie [Records of the 12th Study Day of the Swiss Chronometry Society], 17 September 2008).

Hence Laboratoire Dubois is able to offer its customers a wide range of tests and analyses specific to these materials used increasingly frequently for watch exterior components (straps, gaskets, decorative inserts on the case, crown, push-pieces). These tests are also applicable to components made from thermoplastic or thermosetting materials.

Among the many mechanical and climatic tests available, the ozone oxidation tests is worthy of special mention. Our ozone test equipment, compliant with standard ISO 1431-1, is used to simulate the oxidation, hardening and cracking effects of urban environments.

Combined with exposure to UV light and to mechanical stresses, this test reproduces wearing under varying conditions of severity.

Multiple cracks development on an elastomer under the effects of ozone
FTIR analysis of an elastomer, before and after ageing