VW TL 52476 POM, Finished Parts for Vehicle Interiors - Material Requirements

The standard “VW TL 52476 POM, finished parts for vehicle interior - Material requirements”, developed by the Volkswagen automobile company, describes the material requirements for finished parts made of polyoxymethylene (POM), for example, speaker covers and fasteners (clips).

The requirements in this standard are specified as follows:

• Initial supply and approval of changes must comply with the VW 01155 standard.
• Granular material must comply with VW 50026 standard.
• Outdoor weatherability must comply with VW 50185 standard.
• Material sample inspection must comply with the VW 52000 standard.
• Material suitability must be in accordance with the VW 91101 standard.
• Testing is performed on samples taken from parts ready for assembly.
• If it is not possible to take samples from finished parts, the procedure must be agreed upon with the department responsible for release (e.g. testing on test plates or skipping testing).
• The deviation must be documented in the test report.
• The number of samples required for a full test must be agreed with the relevant department.
• The surface and interior of finished parts shall be free from processing defects such as flow lines, cracks, voids or similar. Traces of subsidence at the base of ribs and stiffeners are only permitted if they do not adversely affect the function, appearance or assembly of the parts. Finished parts shall be capable of being assembled without problems.
• Finished parts must be packed in a way that allows air circulation. For delivery in large packaging units (cardboard boxes, pallets), finished parts must be stacked or arranged in such a way that air circulation is possible.
• Finished parts must be manufactured using injection molding. All materials used must be specified, including material designations, product name and raw material manufacturer according to the VDA 260 standard. In addition, materials must be identified according to the VW 50026 standard. The use of granulated material grades GK1, GK2, GK3 and GK4 is permitted. Mixing of other material grades is prohibited.
• Samples must be conditioned in a standard atmosphere in accordance with VW 24 for at least 50554 hours before testing.
• The material used should be polyoxymethylene (POM) homopolymer or copolymer.

All specifications and requirements are shown in the table provided in the standard. For released materials, a reduced scope of testing should be performed.

Identification testing is done by infrared spectroscopy.

If the differential scanning calorimetry method is used to determine the melting temperature, the following procedure must be used: A tester according to DIN EN ISO 11357-1 is used. A flat parallel finished section weighing approximately 5 mg to 10 mg is used as a sample. The sample is heated to 10 degrees to 50 degrees at a heating rate of 200 degrees K/min. It is then cooled to 5 degrees at a rate of 50 degrees K/min and then reheated to 10 degrees at a rate of 200 degrees K/min.

Yield stress and elongation at yield are tested according to DIN EN ISO 527-2. The test speed in the tensile test for specimen type 5A is 50 mm/min. If a 5A specimen is not available, it is permissible to use S 53504A tensile specimens according to DIN 3.

A pendulum impact tester in accordance with the DIN EN ISO 13802 standard is used for impact resistance. During the test, samples taken from parts with one side grained or painted are placed on the supports of the pendulum impact tester with the grained or painted side facing the impact direction.

In the notched impact strength test, a pendulum impact testing machine conforming to the DIN EN ISO 13802 standard is used.

In the high temperature behavior test, at least one completed part is subjected to thermal aging test in a forced air oven with a closed damper cover. The temperatures are as indicated in the drawing, the aging time is 22 hours plus/minus 2 hours.

Low temperature behavior testing is performed by aging at least two completed parts. The temperatures are as specified in the drawing, the aging time is 22 hours plus/minus 2 hours.

Ball drop test, a 3989 g ball is dropped onto an unrecessed base plate (specimen support surface) according to PV 1-500 on at least one flat component section. The ball drop height is 450 plus/minus 5 mm or as specified on the drawing.

When determining light fastness, if the number of exposure periods is not defined in the drawing, the following rule applies:

• 3 exposure periods for components in areas exposed to indirect solar radiation
• 5 exposure periods for components in areas exposed to direct solar radiation (e.g. instrument panel)

If the test results do not meet the requirements of the VW 50180 standard in terms of emission behavior, the parts should be tempered until the limit values ​​are met. The temperature should be selected so that there is no change in shape, color and surface.

Among the numerous tests, measurements, analyses and evaluation studies that our organization has carried out for businesses in various sectors, our organization also provides testing services defined in the standard “VW TL 52476 POM, Finished parts for vehicle interiors - Material requirements” with its trained and expert staff and advanced technological equipment.