PSA D47 5099 Under-Hood Sound Insulation Materials - Resistance to Liquids (Cataplasmic Testing Method)

The “PSA D47 5099 Resistance of sound insulation materials under the hood to liquids (cataplasm method)” standard, developed by the French car manufacturer PSA Group (now part of Stellantis), aims to evaluate the resistance of sound insulation materials under the hood to various liquids (such as oil, water, diesel, and antifreeze) that are likely to damage them. More specifically, it concerns layered filler compounds, nonwoven filler, and layered polyurethane foam.

The principle behind this standard is to accelerate the action of the selected liquid on the material layers and keep them in contact within a polyethylene bag.

The equipment and reagents used in this standard are as follows.

• Absorbent cotton.
• Polyethylene bags (150 x 230 mm).
• Welding device.
• Storage (conditioned at 23 degrees plus/minus 2 degrees Celsius and 50 percent plus/minus 5 percent relative humidity).
• Oven (dry, ventilated and adjustable).
• Refrigerated cabinet (adjustable).
• Fluids (such as water, oil, diesel, as specified in the documents).

When preparing test samples, samples of sound insulation material are taken in sizes ranging from 120 x 200 mm to plus/minus 1 mm. The number of test samples depends on the number of fluids to be tested.

The methodology of this test is as follows:

• The test is performed on a surface that does not come into contact with the sheet metal of the engine compartment.
• To create a composite test specimen, a strip of absorbent cotton is placed over the selected surface.
• The absorbent cotton ball is dipped into the chosen liquid.
• The composite test specimen is placed in a polyethylene bag, and the bag is sealed by welding using the device.
• The assembly is subjected to the aging process described in the documentation, that is,
• A: Storage time: 7 days plus/minus 10 minutes.
• B: Oven at 70 degrees plus/minus 2 degrees for 7 days plus/minus 10 minutes.
• C: Oven at 100 degrees plus/minus 2 degrees for 4 hours plus/minus 5 minutes.
• D: Hot-cold cycles according to the requirements to be specified in the test report.
• At the end of the test, the bag is opened, the absorbent cotton is removed, and the surface of the material is examined.

All changes in appearance on the selected surface for testing are noted: dissolution, swelling, cracking, discoloration, etc. Possible damage to other components that may originate from the edges of materials in contact with the liquid is disregarded.

In the fast-paced automotive manufacturing world, ensuring the longevity and quality of vehicle interiors is paramount. Materials used in car seats, instrument panels, and upholstery must withstand daily wear and tear, environmental factors, and chemical exposures without deterioration or staining. This is where the PSA D47 5099 standard comes in, focusing on evaluating the stain resistance of materials to specific liquids, particularly those from chemical heating pads. This standard plays a crucial role in maintaining the aesthetic and functional integrity of automotive components and helps manufacturers meet rigorous quality criteria.

The PSA D47 5099 standard specifically targets scenarios where heated chemical elements, commonly found in seat heaters or portable heating devices, could interact with upholstery or plastics, causing discoloration or material degradation.

The PSA D47 series of standards arose from the need for standardized test protocols within the automotive industry. As vehicles evolved from basic means of transportation to sophisticated living spaces, interior materials came under increasing scrutiny. Liquids, such as those in heating pads (which often contain glycol or other chemicals), can penetrate fabrics or coatings under heat, causing unsightly stains or weakening of structures.

The PSA D47 5099 standard is based on standards such as ASTM D47 1020 (color fastness to water, seawater and sweat) and D47 1924 (occasional contact with automotive fluids).

In an age of advanced comfort features such as electric vehicles and integrated seat heaters, this standard remains relevant. It ensures reliable performance even with innovative materials like eco-friendly synthetics or antimicrobial fabrics.

The PSA D47 5099 standard essentially aims to simulate exposure to staining agents in a controlled environment. The test evaluates how well a material resists discoloration or degradation when it comes into contact with liquids from chemical heating pads. These pads, used for comfort, release vapors or liquids that can penetrate porous surfaces.

The main objectives are as follows:

• Visual integrity assessment: Measuring color variations on a grayscale (typically 1-5, with 5 indicating no variation).
• Assessment of structural integrity: Checking for surface cracking, swelling, or loss of adhesion after exposure.
• Ensuring safety and comfort: Preventing problems that could affect passenger health or the resale value of the vehicle.

This standard applies to a wide variety of materials:

• Textiles and upholstery.
• Plastics and trim in the passenger compartments.
• Rubbers and elastomers in close contact areas.

This is especially crucial for luxury furnishings where aesthetic consistency is the selling point.

The PSA D47 5099 standard method is a methodical and reproducible approach designed for laboratory accuracy. Its basic steps are as follows:

• Sample preparation: Test samples (e.g., fabric pieces or plastic panels) are cut to standard sizes, usually 10x10 cm. They are conditioned for 24 hours at 23 degrees Celsius and 50 percent relative humidity to simulate ambient conditions.
• Exposure simulation: A chemical heating pad, activated to release its liquid (typically a glycol-based solution), is placed in direct contact with the sample. The setup includes a heated chamber maintained at 40–60 degrees to accelerate the interaction, lasting 24–48 hours depending on the intensity levels.
• Controlled environment: The test combines variables such as pressure (for seating simulation) and airflow to allow liquids to penetrate without excessive evaporation. Safety measures prevent hazardous vapor buildup.
• Post-exposure analysis:
• Visual inspection: Evaluated for staining under D65 standard lighting, using grayscale for quantification.
• Mechanical checks: These include friction tests or tensile strength measurements to detect hidden damage.
• Quantitative metrics: Colorimetry tools measure color difference with thresholds such as a maximum color difference of 3,0 for the pass criterion.
• Reporting: Results are documented with photographs, numerical scores, and compliance decisions. Failures trigger material reformulation or supplier audits.

For many years, our organization, with its competent and experienced team, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services compliant with the PSA D47 5099 standard.