MAN M 3594 Burning Behavior of Materials - General Requirements, Material Approval, Definitions

The standard "MAN M 3594 Burning behaviour of materials - General requirements, material approval, definitions", published by MAN, an automotive and machine-building company based in Germany, applies to the burning behaviour (flammability, burning rate and melting behaviour) of materials of all components (components and assemblies) installed in the interior of motor vehicles, as well as in the chassis area and in defined parts (e.g. insulation materials) in the engine compartment, as well as of electrical cables, electrical components, cable ducts and cable sheaths installed in the vehicle and compressed air lines of vehicles, in the context of motor vehicles in classes N (goods transport) and M (passenger transport).

The purpose of this standard is to define fire protection requirements for the vehicle classes defined herein and to ensure compliance with these requirements in a verifiable and systematic manner. This ensures that all homologation documentation is available in time for vehicle approval or homologation.

Parts used in the passenger compartment must be installed in a way that minimizes the risk of flame formation and spread. Interior fittings may only be installed in accordance with their intended purpose and subject to the tests to which they are subjected.

In this standard, the requirements for individual components and assemblies are described as follows:

• The materials of all identified parts and interior fittings in the chassis area, excluding glass and metal materials, must meet the test requirements described in this standard. Test specifications must be defined either on the drawing or in the part-specific component load book module 2.
• Composite parts that are rigid across their entire surface must be tested as composites. Components connected at specific points must be tested separately. Composites are tested with a maximum thickness of 13 mm. If the thickness of the composite or individual part exceeds 13 mm, a reduction in the back side of the part must be made.
• If an additional part is used on the bus, the requirements for the bus described in this standard must also be complied with.
• The test is performed on the part in the area of ​​the thinnest component thickness. If the required test specimen geometry cannot be prepared according to ISO 3795 or if the part is too small, rough or smooth test plates at the thinnest component thickness should be used as an alternative. Alternatively, the supplier may select reference parts.
• Test plate production and reference part selection must be organized by the supplier in coordination with MAN. The costs of test samples and their production, as well as the costs of subsequent retrofitting with alternative materials, must also be part of the contract.
• Tests must be conducted on at least five test samples. The highest burning rate determines the overall result. A classification is made in accordance with Annex F in the test report.
• If the material has a composition that could lead to different test results depending on the direction, fire tests should be conducted in both longitudinal and transverse directions. This should be noted in the test report.

The test methods defined in this standard are:

• Horizontal burning rate test: All materials defined in this standard must be subjected to a test rig in accordance with ISO 3795. The test result is considered satisfactory if, considering the most unfavorable test results, the horizontal burning rate does not exceed 100 mm/min or if the flame is extinguished before reaching the final measurement point.

When the test results exceed 75 mm/min, an unrestricted approval for horizontal burning behavior is valid. The table titled "Overview of Tests for Vehicle Interior Components" identifies the individual components for which test values ​​for melting behavior or vertical testing must be specified in addition to the horizontal testing. If the melting behavior and vertical testing values ​​exceed the limit values ​​according to this table, a decision is made in collaboration with the person responsible for the component and those responsible for quality, homologation, and material technology to grant unrestricted approval within the scope of initial sample approval or approval with restrictions considering the installation space.

If the test results are between 75 mm/min and 100 mm/min, the person responsible for the part and those responsible for quality, homologation and material technology will decide, within the scope of the initial sample approval, whether an unlimited approval or approval with restrictions will be granted, taking into account the installation area.

• Melt behavior test: Parts marked with this requirement on the drawing or in module 2 of the component load book shall be subjected to a test in accordance with Annex C. The test result is considered satisfactory if, considering the most unfavorable test results, no drop is formed that would ignite the cotton.
• Vertical burn rate test: Parts marked with this requirement according to the drawing or component load book module 2 must be subjected to a test with a test fixture according to ISO 6941 standard method B (lower edge ignition). The test results are submitted to MAN.
• Checking fuel or lubricant impermeability: All insulation materials installed in the engine compartment and in separated heating compartments must be tested in accordance with Annex D. The test result is considered satisfactory if, after 24 hours, the weight gain in the sample does not exceed 1 g, taking into account the most unfavorable test results. Recesses that must be present for technical reasons (e.g., lines or structural elements that must pass through the material) are only permitted if protective components (e.g., insulation material, adhesive tape) are present.
• Flame propagation resistance test on electrical lines: Electrical cables with a minimum length of 100 mm must be tested for resistance to flame propagation in accordance with ISO 6722-1. Considering the most unfavorable test results, the test result is considered satisfactory if the flame of the burning insulation material is extinguished within 70 seconds and at least 50 mm of insulation remains unburned at the top of the sample. The burning behavior of electrical lines is determined using five samples, each of which must meet the requirements of ISO 6722-1.
• Burning behaviour of electrical, electronic or mechatronic components in accordance with the MAN M 3499-1 and MAN M 3499-2 standards: In accordance with these standards, the burning behaviour of the components installed in the vehicle must comply with the V-0 requirement of the DIN EN 60695-11-10 standard.
• Overview of materials to be tested in the truck interior: The table lists, as an example, which interior parts must be tested according to which section of this standard. This overview table is not exhaustive, especially regarding part-specific components. The requirements are defined in the drawing or in component load book module 2. Parts made of metal or glass do not need to be subjected to certain tests.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with the "MAN M 3594 Burning behavior of materials - General requirements, material approval, definitions" standard.