Smoldering Initiation and Propagation Characteristics of Mixed Melamine Foam and Flexible Polyurethane Foam

By using the self-designed mesoscale (0.60 m × 0.25 m × 0.25 m) smoldering experimental platform, smoldering simulation tests of melamine foam (MAF) and flexible polyurethane foam (FPUF) embedded inside the chamber at different volume ratios (0.0 %-100.0 %) were carried out. Results show that as volume of MAF increases, critical smoldering temperature (CST) first increases to a maximum value of 347.6 °C at 20.0 vol% (MAF) and then decreases, showing.an average value of around 330.0 °C. Heating rate (SHR) of raw materials and char residue keeps decreasing to below 0.2°C/s when MAF volume exceeds 60.0 vol%. Smoldering propagation rate (SPR) first increases to maximum value of 5.6×10–3 cm/s at 20.0 vol% (MAF) and then decreases. As MAF volume upgrades, high temperature maintenance time (HTMT) at different positions gradually decreases with the smoldering wave propagation (B2>C2>D2>E2).