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

Abstract

The transition from smoldering to flaming was studied on fabric, batting, and foam assemblies via an electric spot ignition source of similar intensity to a cigarette. The materials studied included four different fabrics (cotton, polyester, cotton/polyester blend, flame retardant cotton/polyester blend), two types of batting (cotton, polyester), and three types of polyurethane foam (nonflame retardant, flame retardant by FMVSS 302 testing, flame retardant by BS5852 testing). The results from testing found that materials highly prone to smoldering could propagate smoldering into foams and lead to ignition, whereas materials that tended to melt back from the ignition source did not. Flame retardant fabrics or foam can and do prevent the transition from smoldering to flaming provided sufficient levels of flame retardants are incorporated in the upholstery fabric or foam. The transition from smoldering to flaming of cotton fabric/nonflame retardant foam assembly was also studied using temperature measurements and evolved gas analysis. It was determined that the transition takes place when the oxygen consumption by accelerating smoldering front exceeds the oxygen supply. At this point, the solid fuel gasification becomes driven by thermal decomposition rather than by surface oxidation which leads to high enough concentrations of fuel for flaming combustion to occur.

Analysis of a Costly Fiberglass-Polyester Air Filter Fire

“…Transition from smoldering to flaming combustion has been studied extensively in recent years for, e.g., polyurethane foams [17,18], cotton [19], pine needles and wood powder [20], peat [21], and coal waste dumps [22], and since smoldering results in many deaths worldwide, much work has addressed preventing materials for initiating smoldering combustion, e.g., [23]. When it comes to the combination of glass fibers and polymers, several fire-related studies have focused on flaming combustion of glass fiber-reinforced epoxy resins, e.g., [24][25][26].…”

“…For the transition to flaming combustion observed in the full-scale filter tests in the present study, it was not possible to determine the transition mechanisms. Several studies [17][18][19][20] consider the inclination and porosity of tested materials to be important for transition from smoldering to flaming combustion. In the present study, the filter cassettes allowed for inclined and vertical surfaces between individual filter bags where the suddenly fast-developing smoke plumes could be ignited.…”

Interpol review of fire debris analysis and fire investigation 2019–2022

“…Morgan et al studied the transition from smoldering to flaming using an electric spot ignition source (like a cigarette) on different fabrics, batting, and foams [ 176 ]. Results showed that materials prone to smoldering could lead to ignition, but materials that melted away from the ignition source did not transition to ignition.…”

On-Line Thermally Induced Evolved Gas Analysis: An Update—Part 1: EGA-MS

“…The materials studied included different fabrics (cotton, polyester, cotton/polyester blend, flame retardant cotton/polyester blend), batting (cotton, polyester), and polyurethane foam (non-flame retardant and flame retardant by two different testings). The evolved gas analysis allowed us to compare the different behaviors [ 98 ].…”