Smoldering Propagation Characteristics of Flexible Polyurethane Foam under Different Air Flow Rates

摘要

The smoldering characteristics of flexible polyurethane foam (FPU), including smoldering spread, smoldering temperature, and high temperature duration, were studied and analyzed under four different air flow rates, namely 2, 3, 5 and 7 L/min, with mesoscale smoldering simulation device to investigate the smoldering combustion performance of the material. Air was forced in the direction of smolder propagation under conditions that produce approximately one-dimensional forward smolder propagation. Results show that there was an approximately linear relationship between the average smoldering rate and airflow rates. The smoldering velocity along the foam remains almost constant during the propagation process. When air flow rate varies from 2 to 5 L/min, smoldering temperature of FPU increases with the increase of air flow rate. The maximum temperature is 400 °C under air rate of 5 L/min, a peak temperature above 400 °C lies in 5-7 L/min. The duration of high temperature in intermediate location is higher than those at two end locations, FPU is consumed more and strongly at both ends.