PSA D45 5523 Scratch Resistance - (Sclerometer Test)

The purpose of the method described in the standard “PSA D45 5523 Scratch resistance - (Sclerometer test)” developed by the French automobile company Renault is to characterize the scratch resistance of parts made of elastomer or thermoplastic elastomer (sealing strip, channel, window lining, cladding, etc.). The scratch resistance of decorated interior parts (films, screen printing, wood, aluminum, etc.) and paints can also be measured by this test method. The test is preferably carried out on finished parts, but can also be carried out on extruded strips or injection molded plates.

This test consists in principle of testing the surface of a sample for resistance to scratching. The scratches are made manually using a sclerometer equipped with an indenter (a hard metal round tip) and a mechanism that allows the load applied to this tip to be controlled during the test.

The basic instrument used in these tests is the sclerometer. Two types of instruments allow to perform this test, but for better reliability of the measurements the Erichsen sclerometer (body + springs) is recommended, secondly the Braive Instruments sclerometer.

The Erichsen sclerometer contains three types of springs:

• Blue: forces from 0 to 3 N (0,1 N accuracy)
• Red: forces from 3 to 10 N (0,5 N accuracy)
• Yellow: forces between 10 and 20 N (1 N accuracy)

The Braive Instruments sclerometer contains three round tips:

• 0,5mm diameter
• 0,75mm diameter
• 1mm diameter

Other equipment used in these tests includes:

• The flat steel plate has minimum dimensions of 200 x 200 mm and a thickness of 10 mm and serves as a support for the tested samples.
• Double-sided adhesive allows the sample to be held on the support.
• The white wiping cloth is a white, absorbent, lint-free cotton cloth.
• 20 cm graduated scale.
• Indelible pen.
• A controlled environment room is a room with a temperature of 23 degrees plus/minus 2 degrees and a relative humidity of 50 percent plus/minus 5 percent.
• Dynamometer.
• Retaining arm.
• Greyscale is used to assess distortions in accordance with the NF EN 20105-A02 standard. A nine-degree scale with a black border is used.
• The daylight device (light coat) complies with the test method of standard D15 1343.
• 50/50 volume mineralized water / ethyl alcohol solution.

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.

It is recommended that the sclerometer be calibrated every 50 test series, or if these are too far apart. The pieces or strips should be conditioned at 24 degrees plus/minus 23 degrees and 2 percent plus/minus 50 percent relative humidity for at least 7 hours prior to testing.

If possible, the test should be performed on a flat area of ​​the part measuring 200 x 10 mm. By default, or if the part is not sufficiently flat, the test should be performed either on an extruded strip (equivalent to an extruded part) or on an injection molded plate (equivalent to an injection molded part). The mounting conditions and thicknesses should be as close as possible to those of the parts.

The sample is placed on the support. It can be held by double-sided adhesive. The surface of the tested sample is cleaned with a solution using a cloth. When cleaning, the cloth should be well moistened but not too much, and the samples should not be subjected to a certain strain (friction).

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 D45 5523 Scratch resistance - (Sclerometer test)” standard with its trained and expert staff and advanced technological equipment.