PSA D14 1425 Decorative Coatings and Friction Parts - Resistance to Rotary Wear

The standard “PSA D14 1425 Decorative coatings and friction parts - Resistance to rotary wear”, developed by the French automobile company Renault, describes a procedure for checking the resistance to wear of plastic parts with decorative coatings such as metallization, painting, hot stamping, plating and any other internal parts that fall into the category of wear during use, i.e. whose surface may be subject to friction.

In principle, when performing this test, the surface of a test sample is subjected to friction with six strips made of reference fabric, mounted on a device rotating at a certain speed for a certain period of time.

The equipment used in these tests includes:

• Electric motor: Must be equipped with devices that allow it to reach a rotation speed of approximately 200 W, possibly 1400 rpm plus/minus 50 rpm.
• Strip holder device: It consists of a drum mounted on the motor shaft.
• Reference material for strips: Should be as defined in the standard:
  • Type A: Chamois leather, weight per square metre 300g plus/minus 50g.
  • Type B: Textured sealing mesh 100 percent bleached cotton, weight per square meter 215 g, 25/26 warp threads/cm, 41 tex single twist thread or 25/22 weft threads/cm, 41 tex single twist thread.
• Preparation of strips: Strips are cut to a width of 40 mm from reference material A or B. Their length is designed so that their ends are 110 mm away from the rotation axis of the device when mounted on the strip holder device (material A) or folded (material B).
• Timer
• Grey scale: For the assessment of degradations, it must comply with the NF EN 20105-A02 standard. A nine-degree scale with a black edge is used.

Test samples or specimens should be representative of the scale to be characterized. To ensure this representation, it is necessary to find out the basic characteristics of the population under study. Selection criteria for test samples or specimens should be stated in the test report in accordance with the PSA A10 0156 standard. In case of doubt about the sampling, the PSA service should be contacted to obtain the guidelines to be followed.

The test can be performed on entire parts or sections of parts. The rubbed area should preferably be flat or slightly inclined. Sharp angled areas that are less important for the test are eliminated as much as possible.

Test samples and reference fabric strips are conditioned for at least 24 hours at a temperature of 23 degrees plus/minus 2 degrees and a relative humidity of 50 percent plus/minus 5 percent. Tests should be carried out in the same atmosphere.

The steps of the procedure to be applied are as follows:

• Before testing, the test sample is examined and its appearance, shade and similar characteristics are noted.
• The test sample is fixed so that the distance between the surface to be examined and the rotation axis of the device is 90 mm plus/minus 2 mm.
• Prepared strips are placed on the strip holder drum and the end or both ends of the strips are clamped in jaws designed for this purpose.
• The device is kept open for the time specified in the standards.
• At the end of the test, the instrument is stopped and any surface disturbances of the test sample are noted (e.g. abrasion, appearance of the column, contrast quotation according to gray scale).
• New strips are used for each new test.

Any deterioration in appearance, features or weight loss is necessarily reported.

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 standard “PSA D14 1425 Decorative coatings and parts subject to friction - Resistance to rotary wear” with its trained and expert staff and advanced technological equipment.