Self-extinguishing compounds and rail industry: a growing dual concept

Self-extinguishing compounds and rail industry: a growing dual concept

Recent innovations in LATI S.p.A. self-extinguishing thermoplastic compounds have caught the interest of designers operating in the world of rail transport.
In this regard, a factor of primary interest is the absence of halogenated flame retardants and red phosphorus that characterizes the new HF1 formulations.

This is an essential first step towards the reduction of danger of fumes produced by the materials in case of fire.

Equally important are the certifications of conformity to the requirements of the European industry standard EN45545, which states for each tested compound the suitability for use inside or outside of the car based on the fire behavior, as well as the opacity and toxicity of fumes produced during combustion.

Consisting of PA66 with 25% glass fiber reinforcement, LATAMID 66 H2 G/25-V0HF1 is one of the materials expected to become most successful in the railway sector due to its environmentally friendly self-extinguishing formulation, excellent mechanical properties, and especially its compliance to Hazard Levels HL1 – HL2 – HL3 set out in the EN 45545 standard for use both inside and outside of the car body (R22-R23).
The German world-leading company in the field of filtration systems for gases and liquids, has chosen LATAMID 66 H2 G/25-V0HF1 for the manufacture of the fastening systems used in filter elements for air purification of train compartments.

The choice was conditioned not only by the material approvals as per EN 45545, but also by the excellent self-extinguishing properties of the compound, i.e. UL94-V0 up to 0.75 mm, and high resistance to static and dynamic mechanical stresses.
Finally, dimensional stability is critical for the fastening system, which consists of brackets for which the absence of deformation and compliance with geometric tolerances is a necessary condition for proper functioning.

V0HF1 compound family includes grades developed on PA66, PBT, and PPA.
In particular, V0HF1 compounds based on PA66 are offered with 25-50% glass fiber reinforcement and UL certification so as to meet even the most demanding mechanical requirements as, for example, in the case of thermoset replacement.

The new SPDs by ABB for the surge protection

The new SPDs by ABB for the surge protection

ABB’s expertise in electronics and LATI’s expertise in the world of special thermoplastics have given rise to a new product for the protection from transient voltage surges and lightning: PM EP 15 15-275 RES is a pre-wired protective device (SPD or surge protection device) featuring modern design and small dimensions.
Designed for use in control housings and compact power supplies, the new SPD is ideal for use in the new LED systems, especially those dedicated to public spaces, such as parking lots and parks, road signage and lighting, decorative lighting etc.
In fact, these are the light sources that are mostly affected by power grid disturbances, specially industrial or natural (lightning) surges that are captured and amplified by the long electrical connections with power supplies.

Voltage peaks may easily cause failures in LED units if not stopped, thus resulting in service disruption and often expensive and complex maintenance requests.
So here is the perfect ABB solution to be combined with residual current circuit breakers and fuses to preserve the integrity of the systems to be protected.

Both the envelope and terminal blocks of PM EP 15 15-275 RES are made by injection molding of LATAMID 66 H2 G/25-V0HF1, a PA66-based thermoplastic compound formulated by LATI to be self-extinguishing and structural thanks to a 25% glass fiber reinforcement.
The performance of the V0HF1 grade is appropriate from both the structural and flame safety point of view as confirmed by UL and VDE certifications attesting the excellent self-extinguishing properties, as well as the resistance to incandescent wire with GWFI = 960°C at 1 mm.

ABB’s choice fell on the LATI compound not only for its technical performance and the versatility of the material, but also for its total safety and respect for the environment, backed by a RoHS compliant formulation completely free from halogenated flame retardant additives.