PSA D25 5376 Paint Coatings - Resistance to High Pressure Washing

The purpose of the procedure described in the standard “PSA D25 5376 Paint coatings - Resistance to high-pressure washing” developed by the French automobile company Renault is to characterize the resistance of paints, anti-gravel sealants, decorative films and similar coatings to the effects of high-pressure cleaners. This procedure is applied to coatings on sheet metal, plastic or composite supports for tests on samples or complete parts.

In principle, this test method consists of subjecting a paint film, anti-gravel mastic or decorative film etc. to the action of a high-pressure cleaner. The test can be performed on the same substrate but in two different areas with or without damage. The possible separation observed is comparable to that encountered on vehicles when using commercial high-pressure washing facilities or domestic high-pressure cleaners.

Major test equipment used in these tests includes:

• The high pressure washer is a device that allows operation at a temperature of 65 degrees plus/minus 2 degrees with a flow rate of 6,5 L/h plus/minus 0,2 L/h for an effective stabilized pressure of 750 bar plus/minus 50 bar (60 MPa plus/minus 10 MPa).
• The flat jet nozzle is used to produce a jet angle of 40 degrees plus/minus 5 under test conditions. The nozzle has a life of 1000 tests, i.e. 1000 crosscuts or sweeps. If 1000 tests are not reached after one year of use, a jet angle check should be carried out (this is the same check as in the case of nozzle replacement). The nozzle can then be used for more than one year and if 1000 tests are not reached after the second year of use, it should still be replaced. Therefore, the nozzle has a maximum life of two years. This requirement for the nozzle's life means that it has no further use.
• The template is rigid, fixed to the rod and constructed to maintain a constant distance of 100 mm plus/minus 5 mm between the nozzle outlet and the test piece. The template also enables a normal angle to be obtained between the nozzle axis and the sample.
• The cutting tool is a safety device for testing purposes only. Lifespan: 50 tests, i.e. 50 cross cuts.
• The stopwatch is accurate to the second.
• The controller is a system that allows pressure and temperature parameters to be controlled near the nozzle outlet.
• Transparent paper is used in 5 mm x 5 mm tiles to measure the separation surface.
• Thermometer, accuracy to degree
• The oven is used for air conditioning at an ambient humidity of 25 degrees plus/minus 5 degrees.

Test samples should be representative of the scale to be characterized. In order to ensure this representation, the basic characteristics of the studied population must be revealed. Selection criteria for test samples must be stated in the test report in accordance with the A10 0156 standard. In case of doubt about sampling, the PSA Group should be contacted to learn the directives to be followed.

The test pieces should have a minimum dimension of 150 mm x 100 mm (optimum, non-restrictive conditions). In addition, the test pieces should be conditioned at 24 degrees plus/minus 25 degrees and ambient humidity for approximately 5 hours before performing the tests. For paints that crosslink at temperatures below 120 degrees, the same conditioning is applied for 7 days unless specific instructions are given in the reference documents.

Among the numerous tests, measurements, analyses and evaluation studies that our organization has carried out for businesses in various sectors, it also provides testing services defined in the “PSA D25 5376 Paint coatings - Resistance to washing with high-pressure washing machines” standard with its trained and expert staff and advanced technological equipment.