Laminated materials according to DIN EN 45545-2

Fire-resistant laminate materials for railway vehicle construction

Modern rail vehicle construction places particularly high demands on preventive fire protection. Materials used in the interior and in technical assemblies must not only be mechanically robust and electrically insulating, but also meet strict requirements regarding flammability, smoke development, and toxicity.

The relevant standard for this is the EN-45545 2, which defines the fire protection requirements for materials and components in rail vehicles.

Laminated materials – especially glass fiber reinforced laminate materials based on phenol or epoxy resin – have established themselves as high-performance and standard-compliant construction materials.

DIN EN 45545-2 – Requirements for materials in the railway sector

DIN EN 45545-2 classifies materials according to so-called requirement sets (R-sets), for example:

• R1 – Interior trim

• R7 – Wall and ceiling areas

• R17 – technical components

• R22 / R23 – electrical assemblies

In addition, hazard levels (HL1–HL3) are defined.
HL3 represents the highest requirement class and is intended for vehicles with an increased hazard potential.

The evaluation is based on defined testing procedures with regard to:

• Heat release rate

• Flue gas density

• Smoke gas toxicity

• flammability

For designers, this means that materials must be both mechanically suitable and compliant with standards.

Structure and properties of laminated materials

Laminated materials consist of several layers of reinforcing material (e.g. glass fabric) that are impregnated with thermosetting resins and pressed together under pressure and temperature.

Depending on the resin system, different property profiles result:

Phenolic resin-based laminated press materials

• Very good fire behavior

• Low smoke development

• Good mechanical properties

• Typical temperature class: B (130 °C)

Epoxy resin-based laminated molded materials

• Very high mechanical strength

• High tracking resistance

• Good dimensional stability

• Temperature classes up to H (180 °C) are possible

• Flame-retardant equipment available

Due to the glass fabric reinforcement, these materials exhibit high flexural and tensile strength as well as excellent electrical insulation properties.

Typical applications in railway vehicle construction

Laminated composites according to DIN EN 45545-2 are used, among other things, in:

• interior panels

• Carrier and mounting plates

• Control cabinet and control technology

• Electrically insulating assemblies

• Covers and front panels

• Low-voltage applications

Especially in the field of electrical systems, high tracking resistance, thermal stability and mechanical resilience are crucial selection criteria.

Selection criteria for EN 45545-compliant materials

The following aspects should be considered when selecting materials:

• Required set of requirements (R number)

• Hazard level HL1–HL3

• Temperature class (e.g. B or H)

• Mechanical stress

• Electrical insulation requirements

• Component thickness (standard-dependent classification)

It is important to note that the classification is often thickness-dependent and must be checked on a project-specific basis.

Laminated materials as an economical construction solution

In addition to conformity with standards, laminated materials offer further advantages:

✔ High mechanical stability with comparatively low weight
✔ Good machinability and CNC machining capabilities
✔ Dimensional accuracy
✔ Low water absorption
✔ Long-term material stability

They thus represent an economically and technically proven solution for the railway sector.

Expertise in material selection and processing

Dr. Dietrich Müller GmbH supports customers with:

• Selection of suitable EN 45545-2 compliant materials

• Technical consulting for railway projects

• Cutting and mechanical processing

• Series and custom production according to drawings

The combination of materials expertise and processing technology results in tailor-made solutions for applications in railway vehicle construction.

Our Overview of laminated materials according to DIN EN 45545-2.