DIN 53509-1 Rubber Testing - Determination of Resistance to Ozone Cracking - Part 1: Static Conditions

The DIN 53509 standard, prepared by the German Institute for Standardization (DIN), describes a test method for determining the resistance of elastomers (rubber products) to cracking under ozone exposure. Until now, ozone test chambers used were designed according to the DIN 53509 standard. However, the construction of ozone climate simulators was later modified by the DIN ISO 1431-1 standard. Ozone climate chambers and ozone test systems previously manufactured according to the DIN 53509 standard no longer meet the new requirements. Today, devices manufactured according to the DIN ISO 1431-1 standard are widely used for static and dynamic aging tests. This new standard describes procedures intended for estimating the resistance of vulcanized or thermoplastic rubbers to cracking when exposed to air at a specific temperature under static or dynamic tensile stress, containing a specific ozone concentration and excluding the effects of direct light.

The relative ozone resistance of different rubbers varies considerably depending on conditions, particularly ozone concentration and temperature. Therefore, extreme caution is required when attempting to relate standardized test results to service performance. In addition, tests are performed on thin test pieces deformed in stress and for objects in service the severity of attack can be quite different due to the effects of size and the type and magnitude of deformation. Reference and alternative methods for determining ozone concentration are described in the ISO 1431-3 standard.

For the purposes of the DIN 53509-1 standard,

• The expression threshold stress expresses the highest tensile stress that a rubber can be exposed to, at a certain temperature and at a certain concentration, to air containing ozone, after a certain exposure time, without the development of ozone cracks on it.
• The expression limiting threshold stress refers to the tensile stress below which the time required for ozone cracks to develop increases so markedly and can become almost infinite.

Among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors, our organization also provides static conditions testing services for the determination of the resistance of rubber material against ozone cracking, within the scope of DIN 53509-1 standard, with its trained and expert staff and advanced technological equipment. .