DragonCoat: a flexible fire-retardant rubber coating

Trelleborg's DragonCoat ensures that suspension components made of natural rubber directly exposed to a heat source will not ignite for as long as the coating provides a shield, thus delaying the onset of smoke, toxic emissions, and flames. In addition, it has the capability to flex and deform constantly throughout a long service life, while retaining all the natural elasticity of the material.

Bill Mortel, Director of Advanced Technologies at Trelleborg Industrial AVS, comments: "Ever since the Kings Cross fire of 1987, fire safety has been a priority for railways around the world, particularly for underground systems, but also for any vehicles that run through tunnels. The many natural rubber components used in primary and secondary suspensions do not cause fire but are fuels capable of contributing to it. Up until now, there has been no way of protecting against this.

"DragonCoat has no impact on the flexibility or performance of the natural rubber spring and it even enhances the product's oil resistance. For train builders and operators, it represents the first technology to offer a significant degree of fire protection for all the train's vital anti-vibration and suspension components, so helping improve survival rates for passengers. Moreover, the coating has a life expectancy comparable to the component itself, and does not require any changes to the product space envelop"

Trelleborg's DragonCoat is a composite formulation with intumescent properties which are activated when subjected to heat. Extensive testing in the laboratories of Trelleborg Industrial AVS has shown that a suspension component with a volume of 10 litres of natural rubber, when exposed to a gas flame for two minutes, self-extinguishes after approximately 12 minutes, releasing minimal heat and smoke. A similar, unprotected component ignited easily, produces heat and heavy smoke while continuing to burn violently. The coating also offers a considerable reduction in toxic fumes (carbon monoxide and carbon dioxide) to levels compliant with the strictest international regulation (CEN TS 45455 - part 2). Worldwide patents have been applied for and an EU patent is already granted.

DragonCoat can be seen at on the Trelleborg stand, number no. 311 in Hall 9, InnoTrans 2012, or for more information, go to www.trelleborg.com/industrialavs.