Safety Knows No Limit

To ensure that train passengers are safe at all times, the DIN EN 45545-2 series of standards regulates fire protection in rail vehicles. It has been in force since 01 January 2018 and applies in the European Union and numerous other countries. In addition to a general part, the DIN EN 45545-2 standard belonging to this series contains an extensive table of components that must meet the very high and complex requirements for the fire behaviour of plastic components.

The task of the XINOMER developers was to develop a new material for plastic components that meets all the requirements of the standard and, if possible, goes beyond them. Essentially, this involves the following properties:

• Fire behaviour according to DIN EN45545-2. The components used must be such that they limit the spread of fire as much as possible. Furthermore, they should ensure that passengers and accompanying personnel can escape with a high probability without outside help and reach a safe area in case of fire.
• In addition to the lowest possible fire propagation, the smoke density and toxicity of the vapours are an essential criterion.
• Freedom from halogens is a must in order to prevent the development of toxic gases.
• Good resistance to media such as oxygen, oil and UV radiation as well as hydrolysis resistance, i.e. insensitivity to water and moisture, must be given.
• The high flame retardant content should not significantly influence or even reduce other important properties such as notched impact, ageing, flowability, colourability and others.

• To achieve the high requirements of EN45545-2, XINOMER developed a new material based on polypropylene: HFFR 1509*. One of the special challenges in the new development was the addition of flame retardants:

• When flame retardants are added, the mechanical properties suffer, especially the notched impact properties. This effect had to be prevented or compensated for as far as possible by using suitable additives.

• The processing and flowability of the material also deteriorates when flame retardants are added. The developers at XINOMER have therefore optimised the material solution so that it can be processed well with common, existing processes despite the addition of flame retardants.

• At an early stage of development, the Xinomer experts carried out fire tests in the company’s own laboratory to test the required properties. An accredited institute was commissioned with the final fire tests.

*HFFR = Halogen Free Flame Retardant (halogen-free and flame retardant)

The new material HFFR 1509 has passed all fire tests and trials with excellent results. The main points:

• As a certified standard-compliant material, HFFR 1509 fulfils the highest hazard class HL3.
• The solution is free of halogen.
• HFFR 1509 is optimised for economical processing in injection moulding.
• The material has a high impact strength and can be coloured without any problems.

Information about HFFR Compounds click here!