Testing methods for evaluating ozone resistance in plastic and rubber

 

1. Ozone chamber testing:
This method involves placing the rubber or plastic sample in an ozone chamber specifically designed to create controlled ozone-rich environments. The samples are exposed to ozone gas for a specified duration and at a predetermined temperature and humidity level. After exposure, the samples are evaluated for any physical changes, such as cracking, blistering, or discoloration.

2. Ozone crack testing:
This test method is used for assessing the resistance of vulcanized rubber samples to ozone-induced cracking. It involves stretching rubber specimens into a uniform shape and exposing them to ozone in an enclosed chamber. The samples are typically subjected to alternating periods of ozone exposure and relaxation. After a predetermined number of cycles, the samples are examined for the presence of cracks and their severity.

 

3. ASTM D1149 - Standard Test Methods for Rubber Deterioration - Ozone in the Atmosphere (Static and Dynamic):
This ASTM standard provides a comprehensive set of test methods to evaluate the ozone resistance of vulcanized rubber. It includes both static and dynamic ozone exposure tests, which simulate different environments and conditions. These tests assess the effects of ozone on the rubber samples, such as surface cracking, elongation retention, and visual appearance.

 

4. ISO 1431 - Rubber, vulcanized or thermoplastic - Resistance to ozone cracking:
This ISO standard outlines a method for determining the resistance of vulcanized or thermoplastic rubber to ozone cracking. It involves exposing rubber specimens to ozone in a chamber and examining them periodically for any cracks or deterioration. The test duration and ozone concentration can vary depending on the specific requirements of the application.

 

5. Accelerated weathering testing:
In addition to ozone exposure, accelerated weathering tests such as ASTM G155 or ISO 4892-3 can be conducted to evaluate the overall weathering resistance of plastic materials. These tests simulate harsh environmental conditions, including exposure to UV radiation, heat, and moisture. By subjecting the samples to controlled cycles of different weathering factors, the tests can provide insight into the material's resistance to ozone, UV degradation, and other environmental stresses.

 

It is important to carefully follow the specific test procedures outlined in the applicable standards to ensure consistent and accurate results. The choice of testing method depends on the material type, intended application, and industry requirements. Consulting the relevant standards and guidelines is crucial for conducting appropriate ozone resistance testing for plastic and rubber materials.