BS ISO 6505:2021 pdf download – Rubber, vulcanized or thermoplastic — Determination of tendency to adhere to and corrode metals

BS ISO 6505:2021 pdf download – Rubber, vulcanized or thermoplastic — Determination of tendency to adhere to and corrode metals 11.3 Number of metal test strips For each test, use two suitable metal test strips as specified in the material specification or selected from the metals specified in Clause 7. For tests in a wet atmosphere, use only one type of metal in the construction of the test piece “sandwich” in order to avoid electrolytic effects. 11.4 Preparation of surfaces of metal test strips Thoroughly scour the test surfaces of the metal test strips using a slurry of pumice powder (5.3) in water applied with a cotton wool pad until a matt surface is obtained. Thoroughly rinse the metal strips with water (5.4) and then with acetone (5.1) and finally dry in air. If the prepared metal test strips are not to be used immediately after cleaning, store them in a clean desiccator over silica gel for not more than 24 h before testing. 11.5 Determination 11.5.1 Tests in a dry atmosphere 11.5.1.1 Tests using sheet material (square test pieces) Take two rubber test pieces as specified in 9.1.1, prepared as specified in 11.2, and two metal strips of dimensions 25 mm by 100 mm, prepared as specified in 11.4. Place the two pieces of rubber between the prepared surfaces of the metal strips so that they are approximately 40 mm apart and equidistant from the ends (see Figure 1). Align the rubber/metal sandwich so formed in the support jig and apply a (10 ± 0,1) kg weight (equivalent to 122,5 kPa acting on the rubber) to the test piece sandwich. Tighten the two screws, one at each end of the sandwich, with just sufficient force to maintain the clamping force when the 10 kg weight is removed. Remove the 10 kg weight from the jig, place the sandwich in the test chamber (6.3) and maintain it at the test temperature for the test period (see Clause 10). At the end of the test period, remove the sandwich from the test chamber, allow to cool, if appropriate, to standard laboratory temperature and maintain it at this temperature for at least 1 h. Release the screw clamps and carefully separate the metal strips from the rubber test pieces. Examine the surface of the metal previously in contact with the rubber for signs of adhesion and corrosion. Use a magnifying glass (6.5)...