MBN 55555-6 Non-Metallic Materials, Material Systems and Semi-Finished Products - Part 6: Mechanical Testing

The standard "MBN 55555-6 Non-metallic materials, material systems and semi-finished products - Part 6: Mechanical testing," developed by the Mercedes-Benz Group, describes the mechanical testing of non-metallic materials, material systems and semi-finished products. It complements the Group's supply specifications. This standard includes specific test specifications that are not defined or inadequately defined in the MBN, DIN, EN, ISO standards or VDA recommendations.

In this standard, the general requirements are defined as follows:

• To ensure product safety and quality and to meet certification requirements, all relevant legal regulations and laws must be complied with. The Group's relevant requirements also apply.
• All materials, process technologies, component parts and systems must comply with current legal requirements regarding regulated substances and recyclability.
• “DBL 8585 The standard “General requirements - Environmental protection, hazardous substances, hazardous goods negative substance list for material selection” must be complied with.
• Legal requirements and local standards regarding emission behavior in the vehicle interior must be complied with.
• Group-specific provisions regarding emissions from materials and components in the vehicle interior must be met (these provisions are “DBL 5430 It is included in the standard “Indoor emissions and odor”).
• The requirements to be met for nonmetallic materials, material systems, and semi-finished products tested using the tests described must also be documented in company standards. This means that a company standard is only permitted to reference a test in that standard if the company standard to which it refers contains the test requirements.
• In testing non-metallic materials, material systems and semi-finished products, the provisions of the referencing company standard must also be taken into account.

The mechanical tests defined in this standard are:

• Scratch Exposure: This method tests the resistance of leather, artificial leather, and films to fingernail scratches. The tests comply with DIN EN ISO 291. Test samples are conditioned at 23°C and 50% relative humidity for at least 24 hours before testing, in accordance with DIN EN ISO 291. The surface of the test sample should be scratched vertically with a fingernail under light pressure or with a knife. A thumb nail (not freshly cut, as the edge may be sharp) is typically used. For the test, the test sample should be placed on a hard surface (e.g., a glass panel). Visual changes should be assessed (e.g., slight or significant changes in gloss (writing effect), damage, cracks).
• Surface scratching using a chisel: This method tests the behavior of surface materials in response to scratching and abrasion. For example, processed knitted products such as artificial leather and films, as well as leather and lined assembly parts, are tested in this way. The tests comply with DIN EN ISO 291 and VDA 230-218 standards. During the test, the material (the surface of the sample) is tested using a test device through a specific movement of the chisel (one back and forth). An abrasive tool is used in these tests. This tool performs a single movement in one direction and back at an average speed of approximately 170 mm/s, tracing a path of approximately 100 mm. The tool should be equipped with a ramp that first places the chisel on the sample and then lifts it again during the movement. The chisel should move freely vertically along the contact path.

For knitted products, one test sample is taken in the direction of the weave and one perpendicular to the weave (minimum 200 mm x 100 mm). Depending on how the sample is fixed to the test device, the required sample dimensions may vary slightly. For leather, samples (minimum 200 mm x 100 mm) should be taken at various points if necessary. When samples are taken from assembly parts, this should be done according to a documented sampling plan. Test samples are conditioned at 23°C and 50% relative humidity according to DIN EN ISO 291 for at least 24 hours before testing. Some fabric-based materials, such as cotton or wool, may require longer conditioning times.

• Scratch resistance of granular plastic surfaces: This method includes standardized methods for determining the resistance of matt or granular plastic surfaces to single-point concentrated stress (scratch), plane stress (writing), and mechanical stress (writing), as well as for the objective (instrumental) assessment of the change in surface quality after stress (scratch and writing). These tests comply with the standards DIN 5033-7, DIN 5033-8, DIN 55656, DIN EN ISO 291, DIN EN ISO 1518-1, DIN EN ISO 2813, and DIN EN ISO 11664-4. This method involves the quantitative determination of the scratch and writing resistance of matt or rough plastic surfaces. Tests should be performed on plane-parallel test plates. Application to spatially curved surfaces, such as cuts from actual components, will lead to deviations in the results and must be specifically agreed upon between the partners in accordance with this recommendation. Typically, components can only be evaluated qualitatively (visually), using reference samples if necessary. A scratch hardness tester should be used to test for damage on test surfaces. Tests can only be performed on flat, parallel plates approximately 2,0 mm to 3,5 mm thick and 100 mm x 150 mm in size, with identical gates (e.g., film gates) removed from larger plates if necessary.
• Scratch Test of Hot Stamped Labels: This method determines the adhesion strength of hot stamped labels. These tests comply with DBL 5416 and DIN EN ISO 291 standards. Hot stamped labels with different surfaces are tested for adhesion to the edges using two different scratch methods. Method A: Using a cross-cut, labeled components are tested for adhesion using a cross-cut for employee self-monitoring. Method B: Using a laboratory abrasion test, label adhesion to appropriate component sections is tested using the APG 1000 abrasion tester.

The MBN 55555-6 standard also defines the following test methods:

• Exposure to scratches
• Scratching the surface using a chisel
• Subjecting grained plastic surfaces to scratching
• Scratch testing of hot stamped labels
• Martindale friction test
• Friction test with steel heels
• Abrasion resistance of flock
• Abrasion resistance with Crockmeter (friction fabric)
• MIE wear test
• Friction coefficient
• Upper fabric folding test
• Heat resistance - Folded exposure
• Cold resistance - Folded exposure
• Cold resistance - Bending exposure
• Bending resistance
• Hardness test
• Ball drop test
• Tensile strength - Edge yarn tensile strength
• Swab outlier test MT 501
• Indentation distance measurement
• Adhesion properties
• Determination of opacity of non-laminated knitted fabrics
• Determination of bending properties of micro sandwich fabrics
• Peel test for decorative products
• Determination of adhesion properties to foam materials
• Foam adhesion at the interface between the foam and the substrate

Our organization, which has been providing services for many years and meticulously follows developments in science and technology worldwide, carries out testing, measurement, and analysis studies in a wide variety of fields for businesses from all sectors, with a mature staff and extensive infrastructure. Within this framework, we also provide testing services in accordance with the “ MBN 55555-6 Non-metallic materials, material systems and semi-finished products - Part 6: Mechanical tests” standard.