PSA D27 5258 Final Paint Coatings - Painting by Welding Rubber or Thermoplastic Elastomer in Contact with a Liquid

The “PSA D27 5258 Final paint coatings - Painting by welding of rubber or thermoplastic elastomer in contact with a liquid” standard, developed by the French automobile company Renault, describes a procedure for evaluating the effect of staining caused by a liquid in contact with a part made of rubber or thermoplastic elastomer on final paint coatings.

In principle, a boiling solution obtained by immersing a thermoplastic elastomer or rubber sample in a liquid is applied to a closed top paint test tube. After aging, the effect of the boiling on the paint coating is examined. The test can be extended by an accelerated aging of the paint coating in the light. This test should be carried out on samples that are as representative of the industrial process as possible.

Major test equipment used in these tests includes:

• Dyeing test mechanism (details are included in the standard annex)
• Ventilated oven (set to 50 degrees plus/minus 1 degree)
• Average pressure mercury lamp (HPLR 400 or mercury lamp Novalamp RVC 400W or another lamp with the same performance as specified in the standard annex is used)
• Pipette or syringe (graduated 2 mL, 0,1 mL)
• Spectrocolorimeter (45/0 S Spectro-slide guide)
• Test fluids (cold windshield washer fluid: 73 percent ethyl alcohol + 27 percent distilled water + 0,2 percent standard wetting agent di-lauryl sodium sulfate)
• Cleaning fluids (demineralized water or 95 degree denatured ethanol)

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.

Preparation of stained test tubes:

• The dimensions of the dyed test tubes shall be 40 mm x 40 mm. They shall be cut into supports of sufficient size for dye adjustment in accordance with the applicable range.
• Tests must be done at least 4 hours after cooking, or more than 3 months after cooking.
• To better visualize the staining effect, tests should be carried out on a topcoat of light color (preferably white or light gray).

These paint coatings must comply with the appearance level 15 requirement of the PSA B5050 4 standard.

The test procedure is carried out as follows:

The test is carried out with the decoction obtained as follows:

• Sections of approximately 2 mm thickness cut from the material or the part to be tested are immersed in 50 g plus/minus 1 g of test liquid for 24 mL plus/minus 50 mL of test liquid in a ventilated oven at 1 degrees plus/minus 5 degree for 0,2 hours, observing the material mass/test liquid ratio.
• The colorimetric properties of the dyed test tube are measured using a spectrocolorimeter.
• The dyed test tube is fixed to the mechanism by applying a regular clamp.
• 0,4 mL of decoction is poured into the mechanism cell with a pipette.
• It is kept in a fully ventilated oven at 50 degrees plus/minus 2 degrees and protected from light for 24 hours.
• The test tube is removed from the mechanism and cleaned with demineralized water.
• It is dried with denatured ethanol.
• Initial classification is performed by colorimetric measurements using a spectrocolorimeter on the surface in contact with the liquid.
• The test tube is placed under the sun lamp for 24 hours (except where otherwise stated in the reference documents)
• The test tube is kept at 1 degrees plus/minus 23 degrees for 2 hour.
• The second classification is performed by colorimetric measurements using a spectrocolorimeter on the surface in contact with the liquid.

The rating shall be carried out by calculating the colorimetric differences between the surface exposed to staining and the surface not exposed to staining, expressed in accordance with the requirements of the PSA D15 5084 test method. In addition to the rating, it shall be stated whether the observed staining was obtained without or after exposure to the sunlamp. Any staining and other deformities caused by swelling or slight loss of gloss shall be eliminated.

Among the numerous tests, measurements, analyses, and evaluations our organization provides for businesses in various sectors, we also offer testing services defined in the "PSA D27 5258 Final paint coatings - Painting by welding of rubber or thermoplastic elastomer in contact with a liquid" standard, thanks to our trained and expert staff and advanced technological equipment.