Klass.-Nr. 55 10 4 August 2002

Plastic Interior ComponentsTesting of Scratch Resistance

PV3952

KonzernnormDescriptors: plastic, interior, component, scratch resistance, crosscut test, test

Page 1 of 4Fachverantwortung/Responsibility Normung/Standards (EZTN, 1733)

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Parties to a contract can only obtain this standard via the responsible procurement department.

VOLKSWAGEN AG

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1 Scope

This test standard serves to determine the scratch resistance of painted and unpainted plastic inte-rior components. A scratch test (crosscut test) is performed on the surface of the component to thisend.

2 Designation

Scratch resistance acc. to PV 3952

3 Definition

The scratch resistance of plastics is defined as the resistance offered by the material to a mechani-cal stress, e.g. scratching motion of a sharp edge or rounded object.

4 Requirements

Requirements and deviations from the test procedure according to the technical supply specifica-tion and/or release.

5 Test

5.1 Principle

A machine-guided scratching gouge scratches a grid with a spacing of approx. 2 mm onto apainted/unpainted plastic surface. Each scratch is produced by one movement in one direction. Acolorimeter is then used to determine the chromatic aberration in relation to the unscratched sur-face.

5.2 Test equipment and auxiliary equipment

- Scratching device (e.g. motor-driven crosscutting tool, from Erichsen, model 430; see Figures1 and 2)

- Scratching gouge (e.g. hard metal tip ∅ = 1 mm; the engraving tip of the 318 hardness testingdevice from Erichsen is suitable)

- Colorimeter acc. to DIN 5033-4- Measurement shapes acc. to DIN 5033 –7 section 3.2.1 - 45°/ 0° or section 3.2.2 - 0°/ 45°

(ideal 45° circular)Other shapes are also permissible upon agreement with the test laboratories.

- Visual evaluation under standard light acc. to DIN 6173 Parts 1 and 2- Standard light D65 (minimum requirement: quality grade 2)

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Page 2PV 3952: 2002-08

5.3 Specimen

The specimens must be removed from the components under test and should be of a shape andsize that ensures plane contact with the specimen holder and the supporting table of the respectivespectrophotometer. The test surface must be plane parallel with the contact surface.

5.4 Specimen preparation

The surface of the specimens must be homogeneous and must have no foreign matter. Specimensshould only be handled with clean, grease-free hands.

5.5 Conditioning

The specimens must be conditioned for a minimum of 48 h in a standard climate according toDIN 50 014-23/50-2.

5.6 Procedure

The test is performed at (23 ± 5)° C.

A scratching tool is used to scratch a grid (crosscut grid) of at least (40 x 40) mm. See Figure 3.

Testing parameters:

- Contact force F = 5 N and 10 N (for unpainted components; F is dependent onthe position in the vehicle and the component specifications)F = 10 N (for painted components)

- Scratching speed v = 1,000 mm/min- Grid spacing 2 mm- Scratching gouge Ø 1 mm (e.g. engraving tip from the 318 hardness testing device

from Erichsen)

Page 3PV 3952: 2002-08

Figure 1 -

Figure 1

Figure 2

Specimenmounting

Page 4PV 3952: 2002-08

Figure 3

5.7 Evaluation

The measured values for dL*, da*, db* and dE* of the unscratched area from the scratched area,determined using colorimetry, are used for evaluation (measured value = mean of at least 5 indi-vidual measurements).

Measuring method acc. to DIN 5033-4

Color change acc. to DIN 6174

Illuminant: D65 / 10°

Measuring field diameter: ≥ 7 mm

In addition, a test of the measured values for plausibility of the optical impression must be per-formed (even when the measurements indicate an evaluation of OK).

6 Referenced standards

DIN 50 014 Climates and Their Technical Application; Standard Climates

DIN 5033-4 Colorimetry; Spectral Method

DIN 5033-7 Colorimetry; Measuring Conditions for Object Colors

DIN 6173-1 Color Sampling; General Color Sampling Conditions

DIN 6173-2 Color Sampling; Lighting Conditions for Artificial Medium Daylight

DIN 6174 Colorimetric Determination of Color Intervals with Object Colors Accordingto the CIELAB Formula

Grid spacing 2 mm

Grid widthapprox. 40 mm