TY - JOUR A1 - Schartel, Bernhard A1 - Bartholmai, Matthias A1 - Knoll, Uta T1 - Some comments on the use of cone calorimeter data JF - Polymer degradation and stability N2 - The cone calorimeter has become one of the most important and widely used instruments for the research and development of fire retarded polymeric materials. The paper addresses three important ways in which the principal setup influences the results — factors which sometimes do not receive due consideration when drawing conclusions. The paper discusses in detail the impact on cone calorimeter results of the choice of external heat flux, the influence on the peak of heat release rate of sample thickness and thermal feedback from the back of the sample, and the influence on irradiance of the horizontal and vertical distances from the cone heater. KW - Cone Calorimeter KW - Fire retardancy KW - Fire testing KW - Nanocomposites KW - Intumescence PY - 2005 DO - https://doi.org/10.1016/j.polymdegradstab.2004.12.016 SN - 0141-3910 SN - 1873-2321 VL - 88 IS - 3 SP - 540 EP - 547 PB - Applied Science Publ. CY - London AN - OPUS4-7211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Bartholmai, Matthias A1 - Knoll, Uta T1 - Some comments on the main fire retardancy mechanisms in polymer nanocomposites JF - Polymers for advanced technologies N2 - Barrier formation and increasing the melt viscosity are addressed as the two main general fire retardancy mechanisms of polymer nanocomposites. They result in specific impacts on fire properties that consequentially cause varying flame retardancy efficiency in different fire tests. The barrier formation retards mainly flame spread (peak of heat release rate) in developing fires, but does not reduce fire load (total heat evolved), ignitability or flammability (limiting oxygen index, UL 94). Furthermore, this flame retardancy effect increases with increasing irradiation and vanishes with decreasing irradiation. The increased melt viscosity prevents dripping, which is beneficial or disadvantageous depending on the fire test used. In some test, it become the dominant influence, transforming self-extinguishing samples into flammable materials or causing wicking. Advantages and the limits are sketched comprehensively for exploiting the main general fire retardancy mechanisms of polymer nanocomposites. It is concluded that barrier formation and changing the melt viscosity in nanocomposites are not sufficient for most applications, but must be accompanied by additional mechanisms in special systems or in combination with other flame retardants. KW - Flame retardance KW - Nanocomposites KW - Organoclay KW - Cone calorimeter KW - Flammability PY - 2006 DO - https://doi.org/10.1002/pat.792 SN - 1042-7147 SN - 1099-1581 VL - 17 IS - 9-10 SP - 772 EP - 777 PB - John Wiley & Sons, Ltd. CY - Chichester AN - OPUS4-13868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -