Epiradiateur Test

Fig. 3.103 Principle of Epiradiateur test according to AFNOR NF P 92-501-1985 1 U-shaped frame 2 connecting element 3 spacer ring 4 clamping screw 5 specimen 6 non-combustible rear plate 7 linear burner. Dimensions in mm... 

Phosphorus containing compounds offer another route to provide halogen-free flame retardancy in thermoset composites. Ammonium polyphosphate materials promote carbonaceous chars that are bound into a vitreous coating formed by the polyphosphate decomposition products. The smoke density emitted from such systems in a fire easily satisfies the requirements of the German Bundesbahn, the French Epiradiateur test for irradiated surfaces, and Airbus requirements for smoke and toxicity. 

These extmsion grades produce low levels of smoke, aroimd half of a comparable PPO alloy, and on a par with rigid PVC, often the main material chosen for many extruded electrical components such as ducts, conduits, etc. Bayblend FR 3030 even satisfies the Airbus Industrie demands on toxic fumes potentially released in aircraft cabins. It also achieves V-0 at 1.6 mm in UL94 and 1 mm components pass the glow wire test at 960 °C. The materials pass the Epiradiateur test for building panels and the German Bundesbahn test for parts in railway vehicles. 

A description is given of the initiatives carried out within the European Community for the harmonization of fire testing. The technical and economic reasons are explained for such initiatives, which are taken in order to remove barriers to trade from the European internal market. Of the various fire aspects, only fire reaction testing is taken into consideration here, because it appears as a major technical obstacle to the free circulation of construction materials. All possible approaches are considered for the attainment of such a harmonization and one, the so called interim solution, is fully described. The proposed interim solution, is based on the adoption of three fundamental test methods, i.e. the British "Surface Spread of Flame", the French "Epiradiateur" and the German "Brandschacht", and on the use of a rather complicated "transposition document", which should allow to derive most of the national classifications from the three test package. 

There may be cases where FR additives will be required in order to pass severe fire specifications, like the Ml classification of ihe French Building Standard using the Epiradiateur Radiation Test. Also, under the EU Building Products Directive there is now a move to harmonise national fire legislation and testing. The new spread of flame test or SBI test may require some increase in the fire retardancy of current rigid PVC formulations. 

A special grade meets the demand for halogen-free materials for pultruslon, resin transfer moulding, filament winding, and hand lay-up processes, giving highly retarded composites at a comparatively low addition rate. With this additive, at approximately 50 parts per hundred resin (phr), the Epiradiateur NF 92-501 test - one of the most stringent in Europe - can be passed with a classification of Ml, where 250 phr is required with aluminium hydroxide. With epoxy resins, the same low smoke density is produced as with polyester laminates, at addition levels of 20-50 phr. The aviation standard FAR 25.8 53 can be passed with an addition of 25-35 phr. A liquid-form additive is available where no powder additive can be used. 

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