Scope:

Chlorine compounds are added to potable water for disinfection. Rubber articles get exposed in service to chlorine compounds. The exposure may be perpetual or periodic and at different temperatures. As a result of exposure, the properties of rubber articles may deteriorate. Thus, affecting their operations. In service, this process takes a long time. Therefore, in this test, the effects of chlorine compounds are accelerated to simulate service conditions, but the test may not give a direct correlation with part performance under actual service conditions. This test yields comparative data on which to base judgment on expected service quality. ASTM D6284-09 test method is suitable for compliance testing, quality control, and research and development work.

Test Procedure:

In ASTM D6284-09 test method, the liquid in which rubber will be immersed contains chlorine compounds, including hypochlorous acid (HOCl), hypochlorite ions (OCl), and monochloramine (NH2Cl). Mass, volume, and hardness of the rubber samples are measured. Rubber samples are immersed in an aqueous solution of chlorine compounds, under defined conditions, for a specific time. Mass, volume, and hardness are measured again. The resulting deterioration is measured by changes in mass, volume, hardness, and appearance of the test piece surfaces and test liquid after immersion.

Specimen Size: 

There are three types of test specimens: Type 1, Type 2, and Type 3. All three types should be about 50 mm in length and 25 mm in width. However, Type 1 should be 1 mm thick. And Type 2 and Type 3 should be 2 and 4 mm thick respectively. 

• Type 2 specimens should be cut from standard vulcanized sheets prepared per Practice D3182. Sheets for Type 1 and 3 specimens should be vulcanized in molds modified for cavity depth. 

• Type 1 specimens are preferred for accelerated testing. Types 2 and 3 specimens are specified by mutual agreement between the producer and the purchaser. 

Data: 

The percent change in mass, volume, and hardness, after immersion is reported. The appearance of the test piece surfaces and test liquid after immersion.