VW PV 3968 Leather Soiling (accredited)

Our test laboratory performs testing in accordance with Volkswagen PV 3968 using accredited procedures. The test specification describes a standardized method for determining the soiling behaviour of leather. The test evaluates the extent to which a defined soiling and rubbing exposure affects the visual appearance of the leather surface.

The test is particularly relevant for leather surfaces in vehicle interiors that are regularly exposed to contact and friction during use and may therefore be susceptible to visible soiling. Typical applications include seat covers and other leather-covered interior components. The test supports material and surface selection as well as quality assurance of leather for automotive applications.

Test procedure according to VW PV 3968

The test is carried out using a Martindale abrasion tester with a pilling attachment, based on DIN EN ISO 12945-2. A defined cotton denim fabric containing indigo, sulfur black and sebum is used as the soiling medium. Before testing, both the leather specimens and the soiling fabric are conditioned for at least 24 hours at 23 ± 2 °C and 50 ± 5 % relative humidity.

The leather specimen is mounted on the lower plate of the Martindale tester, while the soiling fabric is fixed in the pilling holder. The test is performed under a defined pressure of 12 kPa. After 1,000 rubbing cycles, the leather specimens are removed from the test apparatus and evaluated.

Evaluation of soiling behaviour

The soiled leather specimens are visually compared with an untreated reference specimen. Evaluation is carried out using the grey scale according to DIN EN 20105-A02, and the results are expressed as grey scale ratings. Intermediate ratings may also be assigned.

PV 3968 thus enables a reproducible and comparative assessment of the susceptibility of different leather materials and leather surfaces to a defined soiling exposure. The results are particularly relevant for material selection, product development and quality assurance of leather used in vehicle interiors.

Relation to other standards and Volkswagen test specifications

VW PV 3968 is closely related to the Martindale test methods according to DIN EN ISO 12945-2 and DIN EN ISO 12947-1. The test equipment and procedure are based on these standards, while PV 3968 specifies particular conditions for testing the soiling behaviour of leather.

Within the Volkswagen test specifications, there is a direct relationship to PV 3356. While PV 3356 evaluates the soiling and subsequent cleaning behaviour of textiles, PV 3968 specifically assesses the soiling behaviour of leather. Both methods use a defined soiling exposure with a Martindale tester and thus enable the evaluation of surface materials for vehicle interiors.

Application in vehicle interiors

PV 3968 is particularly relevant for leather surfaces whose visual appearance should be maintained despite repeated contact with clothing and other potential sources of soiling. This applies especially to seat leather and other frequently touched leather surfaces in automotive interiors.

The defined soiling procedure enables different leather qualities and surface finishes to be tested under comparable conditions and their suitability for demanding applications in vehicles to be assessed.