EN ISO 20567-2-2017 pdf download.Paints and varnishes – Determination of stone-chip resistance of coatings – Part 2: Single-impact test with a guided impact body (ISO 20567-2:2017)
5 Apparatus and materials
Ordinary laboratory apparatus, together with the following.
5.1 Single-impact tester.
Figure 1 shows the upper part of the test apparatus.
Eigure2 shows the shape of the impact body and its dimensions. The impact body shall be made of hardened steel (hardness 60 [IRC to 66 HRC).
The test panel is inserted on the tester with the wedge-shaped end of the impact body touching the coated test panel and the spring exerting a slight pressure on the body. A steel ball of mass inferior to that of the impact body is accelerated by a compressed-air blast (p = 300 kPa) and transmits part of its energy to the impact body, which then strikes the test panel.
NOTE 100 kPa = Ibar.
The impact body shall be checked, and replaced if necessary, after a maximum of 500 test runs (I.e. after 500 impacts) or at the end of the series of tests during which the impact body passes the point at which it has been used for a total of 500 test runs.
6 Test panels
6.1 Substrate
Use test panels of at least 100 mm x 100 mm in size that are at least 0,7 mm thick.
6.2 Preparation and coating
Prepare each test panel in accordance with ISO 1514 before coating and drying or stoving it. Use the application method specified by the paint manufacturer.
6.3 Thickness of the coating
Determine the thickness, in micrornetres, of the dry coating by one of the procedures specified in ISO 2808
7 Procedure
7.1 Calibration
Instructions for the calibration of the tester are given in Anne.&.
7.2 Conditioning of the test panels
Condition the test panels for at least 16 h at (23 ± 2) °C and (50 ± 5) % relative humidity before carrying out the test (in accordance with ISO 3270).
7.3 Test conditions
Carry out the test at room temperature, i.e. 18 °C to 28 °C. State the temperature in the test report.
After conditioning, ensure that condensation does not form prior to or during the test.
7.4 Number of test runs
Unless otherwise agreed, each test shall comprise three test runs.EN ISO 20567-2 pdf download.