The object of this test method is to determine the changes in properties on elastomers, which are continuously and directly exposed to the urea solution AdBlue® during the exhaust after-treatment of diesel engines.
This test method can provide data for- qualification tests on different elastomers which are in question for a specific application (quality determination),- comparison tests on different delivery batches of a specific elastomer compound (quality assurance).
Tests are performed preferably with the test pieces described in section 3.1. With regard to the influence of test piece shape (thickness, volume, aspect ratio and others) and the nature of the test piece (vulcanization skin on one side or allround, ground surface and others) the tests can be performed on finished parts as well.Standard dumbbells Type 3 and Type 4 to ISO 37 are permissible for the testing of finished parts.The usage of other specimen, e.g. whole finished parts or sections of finished parts must be agreed upon.Test comparisons can only be done on test pieces with same geometry.The time between vulcanization and testing of elastomers shall be at least 16 h and not longer than 6 months when investigating to this procedure.The specific requirements for material properties in new condition and after contact with AdBlue® may differ between the individual OEMs and are therefore expressly excluded from the scope of this Recommendation.The materials, material descriptions and application examples are not listed in this VDA Recommendation. Reference is made in this regard to the relevant specifications of the individual OEMs.