Apparatus for the vertical orientation cone calorimeter testing of flexible polyurethane foams

Abstract

Summary Of concern to regulators and fire safety engineers is how flexible polyurethane foam drips and flows during burning. Specifically, flexible polyurethane foam forms a burning ‘pool’ of liquid as the foam decomposes, which can lead to accelerated flashover events. To fully study this phenomenon where the ‘pool fire’ accelerates heat release, large‐scale tests like the furniture calorimeter (American Society of Testing and Materials (ASTM) E1537) are used, and no small‐scale technique exists. In this paper, we present our work in developing a new sample holder that works with a bench‐scale heat release test, the cone calorimeter (ASTM E1354). The holder was built upon designs developed by the National Institute of Standards and Technology, which placed the foam in a cage in a vertical orientation during cone calorimeter testing. In this paper, we show the schematics for this test apparatus, as well as results obtained with this apparatus on four different flexible foams (shape memory and high‐density foam, flame retarded and non‐flame retarded). We compare the results from the vertical testing with that obtained via traditional horizontal ASTM E1354 testing. The advantages and disadvantages of this new apparatus are discussed in this paper. Copyright © 2014 John Wiley & Sons, Ltd.

Bubbles and collapses: Fire phenomena of flame‐retarded flexible polyurethane foams

“…For the investigation of the dripping behavior, the cone calorimeter setup was changed to vertical orientation to ensure melt flow and to enhance dripping during the test 34,35 . The conical heater of the cone calorimeter was brought into an upright position and a foam specimen with dimensions of 100 × 100 × 50 mm 3 was placed in vertical orientation at a distance of 25 mm.…”

Studying smoldering to flaming transition in polyurethane furnituresubassemblies: Effects of fabrics, flame retardants, and material type

“…A combination of high temperature and absence of oxygen at these elevations produces conditions where the smoldering reactions effectively cease, while the thermal decomposition reactions of the PU foam become dominant. These thermal decomposition reactions are known to generate highly flammable gaseous species 30,31 …”

Revisiting flexible polyurethane foam flammability in furniture and bedding in the United States

“…[26][27][28] The chemical products of thermal decomposition are themselves high heat release materials, [29][30][31] but as the polyurethane decomposes, it begins to liquefy and collapse into a burning pool of decomposition products. 26,27,32 A visual example of this is shown in Figure 2, 33 affected by both air flow and heat transfer. 28,[46][47][48] Regardless of what still can be learned about smolder to flaming transition, any event that causes the flexible polyurethane foam to ignite and undergo flaming combustion presents a significant fire risk for the many reasons described above.…”

“…The chemical products of thermal decomposition are themselves high heat release materials, 29‐31 but as the polyurethane decomposes, it begins to liquefy and collapse into a burning pool of decomposition products 26,27,32 . A visual example of this is shown in Figure 2, 33 but other examples exist. Indeed, recent studies at NIST have focused on apparatus that can capture how the flexible polyurethane foam liquefies and pools under furniture items, which in turn percolates and/or breaks through fabrics and results in rapid flare‐ups of burning liquid polyurethane decomposition products 34 .…”