VW 2.8.1 Elastomers - Material Requirements and Testing

The standard "VW 2.8.1 Elastomers - Material requirements and testing" developed by the Volkswagen automobile company describes the material requirements and test methods for elastomer materials used in components and technical molded parts in motor vehicles. This standard does not apply to vehicle tires.

The requirements in this standard are specified as follows:

• Initial supply approval and changes must comply with the VW 01155 standard.
• Avoidance of hazardous substances must comply with the VW 91101 standard.
• Must not contain DOTG (di-o-tolylguanidine) and its breakdown product o-toluidine.
• Elastomer qualities are tested on components, component sections or, in exceptional cases, on test plates.
• In principle, samples must be delivered with the manufacturer's quality description stated.
• The number of pieces required for laboratory evaluation must be agreed with the responsible materials laboratory.
• Deviations from this standard must be noted on drawings and test reports.
• A separate technical supply specification is required for parts that cannot be classified according to this standard.
• For the recycling of vehicles and powertrains, components are marked as specified in standard VDA 260. For this purpose, codes in accordance with the standard “DIN ISO 1629 Rubber and latexes - Nomenclature” must be used.

The codes listed in the standard only represent an incomplete selection. In principle, the raw polymer materials for the components should be specified as specified in the DIN ISO 1629 standard.

• ACM Copolymers composed of ethyl acrylate (or other acrylates with a small fraction of monomer that facilitates vulcanization (normally called acrylate rubber))
• AEM Copolymer of ethyl acrylate (or other acrylates) and ethylene
• BR Butadiene rubber
• CM Chlorinated polyethylene
• CO Polychloromethane oxirane (normally called epichlorohydrin rubber)
• CR Chlorophene rubber
• CSM Chlorosulfonated polyethylene rubber
• ECO Copolymer of ethylene oxide (oxirane) and chloromethyl oxirane (also called epichlorohydrin copolymer or epichlorohydrin rubber)
• EPDM Terpolymer consisting of ethylene, propylene and a diene with an unsaturated portion in the side chain.
• EPM Ethylene propylene copolymer
• FKM Fluorocarbon rubber containing fluorine, perfluoroalkyl or perfluoroalkoxy groups in the polymer chain.
• FVMQ Silicone rubber with methyl, vinyl and fluorine groups in the polymer chain
• IIR Isobutene isoprene rubber (normally called butyl rubber)
• NBR Acrylonitrile butadiene elastomer
• NR Natural rubber
• SBR Styrene butadiene rubber
• VMQ Silicone rubber with methyl and vinyl groups in the polymer chain

At the time of delivery, the components must have a flawless surface texture. Stickiness, inclusions, voids, cracks, damage and similar faults are not allowed.

Features and degrees are included in the tables given in the standard.

In fuels, oils or greases, the volume shall be equal to 80 plus/minus 5 times the volume of the test sample. Test vessels conforming to the PV 3323 standard (and also sample holders during aging in liquids) shall be used. The tolerances specified in the VDA 674 002 standard apply to the specified aging times. Unless otherwise stated, measurements shall be taken 30 minutes after the sample has been removed from the test environment. Samples shall be cleaned immediately after removal with a lint-free cloth. Test conditions deviating from this standard shall be stated in the drawings and test reports.

The tests are carried out on S53505A barbell specimens according to DIN 3. These specimens must be taken from finished parts. For certain finished part dimensions (e.g. radial shaft seal), S3 standard test specimens can be used as an alternative. In exceptional cases, if the standard test specimens cannot be removed from finished parts, for example with a band knife separating machine, test plates (thickness 2 mm) can be used.

In cases where a hardness other than the preferred hardness must be used, the selected hardness must be stated following the class description. In such cases the tolerance is always plus/minus 5 Shore A.

High temperature ageing is carried out for 53508 hours in a forced air oven in accordance with DIN 94. In justified cases, other ageing periods can be agreed. Measurements are carried out at room temperature (23 degrees plus/minus 2 degrees).

The standard also includes requirements for aging in contact with substances such as gasoline, diesel fuel, fatty acid methyl ester (FAME), petroleum, oil, grease and coolant additive.

The samples are pre-dried for 2 to 4 hours at room temperature and then dried for 53508 hours at 85 degrees in a natural convection oven according to DIN 22. The samples should be aged in such a way that there is complete air circulation around them.

Among the numerous testing, measurement, analysis and evaluation studies that our organization has carried out for businesses in various sectors, it also provides testing services defined in the “VW 2.8.1 Elastomers - Material requirements and testing” standard with its trained and expert staff and advanced technological equipment.